Background/Objectives: Spontaneous intracerebral hemorrhage (sICH) is a particularly severe subtype of stroke, characterized by high rates of mortality and long-term disability, for which robust prognostic markers are still lacking. The aim of this study was to assess the relationship of the ICH score, the National Institutes of Health Stroke Scale (NIHSS) score, and serum high-sensitivity cardiac troponin I (hs-cTnI) levels with 30-day mortality in patients with sICH. Methods: We conducted a prospective observational cohort study enrolling 100 consecutive patients diagnosed with sICH based on neuroimaging findings. Demographic data, clinical parameters, neuroimaging findings, and serum hs-cTnI levels were collected on admission. Subsequently, the ICH score, its individual components, and the NIHSS score were assessed. Results: Patients who died were older and had significantly higher ICH and NIHSS scores, lower Glasgow Coma Scale (GCS) scores, larger hematoma volumes, more frequent intraventricular hemorrhage (IVH), and elevated hs-cTnI levels compared to survivors. Serum hs-cTnI concentrations were significantly correlated with ICH and NIHSS scores, lower GCS scores, larger hematoma volumes, and the presence of IVH. On univariate logistic regression, higher ICH score, NIHSS score, and hs-cTnI level were associated with mortality, whereas multivariate analysis identified the GCS score, hematoma volume, and IVH score as significant independent factors related to fatal outcome. Conclusions: Individual components of the ICH score may provide useful information on outcomes in patients with sICH. Higher serum hs-cTnI levels were associated with 30-day mortality but were not independent predictors. These markers may assist in patient monitoring and support established clinical procedures in therapeutic decision-making. Nevertheless, larger multicenter studies are needed to further clarify their clinical implications in sICH management.

Background/Objectives: Congenital anomalies of the kidney and urinary tract (CAKUTs) represent the leading cause of pediatric chronic kidney disease, yet the molecular mechanisms underlying these malformations remain incompletely understood. While genetic studies have identified numerous CAKUT-associated genes, conventional knockout approaches often result in embryonic lethality or fail to reveal tissue-specific gene functions. This review aims to synthesize findings from conditional knockout mouse studies that have elucidated the spatiotemporal requirements of key signaling pathways during kidney development. Methods: We conducted a narrative synthesis of studies employing Cre-loxP conditional gene targeting in mouse models, identified through systematic searches of PubMed and cross-referencing of key primary research. Studies were selected based on their use of lineage-specific Cre drivers (Six2-Cre, Hoxb7-Cre, Foxd1-Cre) to investigate nephron progenitor maintenance, ureteric bud branching morphogenesis, and stromal–epithelial interactions. Results: Conditional knockout studies have redefined CAKUT pathogenesis as a disorder of dose-dependent signaling, temporal regulation, and inter-compartmental communication. WNT/β-catenin signaling operates in a biphasic, dose-dependent manner in nephron progenitors, with Six2-Cre-mediated β-catenin deletion causing premature progenitor depletion. BMP and FGF pathways demonstrate dose-dependent and context-specific functions in progenitor maintenance, while GDNF/RET signaling is essential for ureteric bud outgrowth and branching. Importantly, stromal-specific deletions have uncovered non-cell-autonomous mechanisms regulating nephron formation. Haploinsufficiency studies demonstrate that partial pathway disruption can reduce nephron endowment without overt CAKUT, predisposing to adult-onset hypertension and chronic kidney disease. Conclusions: Conditional gene targeting has mechanistically redefined CAKUT from a collection of structural malformations to a spectrum of disorders arising from quantitative perturbations in lineage-specific signaling networks. These findings establish that phenotypic severity is determined by the degree of pathway disruption, the developmental timing of insult, and the compartment affected, providing a framework for interpreting oligogenic interactions and variable penetrance in human CAKUTs.

Background and Objectives: Mitogen-activated protein kinases (p38, JNK, ERK1/2) regulate key cellular processes essential for kidney development. Disruptions in these signaling pathways can lead to congenital anomalies of the kidney and urinary tract (CAKUT), a major cause of pediatric kidney disease. This study investigates and compares the expression of these molecules in normal fetal kidneys and CAKUT-affected tissues. Materials and Methods: Forty-three human fetal kidney samples, including controls and specimens with horseshoe, hypoplastic, and dysplastic kidneys, were analyzed across developmental phases 2–4 using immunofluorescence. Quantitative image analysis and statistical comparisons were performed between developmental stages and phenotypes. Results: ERK1/2 expression increased during late development in control kidneys but was significantly reduced in hypoplastic kidneys. p38 showed phase-dependent alterations, with early upregulation in dysplastic kidneys and late elevation in horseshoe kidneys. JNK exhibited significant phase-dependent upregulation in horseshoe kidneys. P38 displayed dynamic expression associated with nephron maturation. Conclusions: MAPK pathways show distinct developmental and phenotype-specific expression patterns in human fetal kidneys. These differences reflect divergent pathogenic mechanisms in CAKUT and may support improved molecular characterization of congenital renal anomalies.

Background/Objectives: Patients with local/locally advanced gastric cancer (GC) undergo gastrectomy/lymphadenectomy, but recurrences are common and the disease usually progresses to death. Tertiary lymphoid structures (TLS) of varying maturity can be observed in the immune microenvironment of the primary tumor. The aim of the study was to analyze the association of TLSs and their immune cellular composition with clinicopathological variables and overall survival (OS). Methods: In a cohort of 92 GC patients who underwent gastrectomy, the characteristics of tumor core TLSs were assessed and the density of cytotoxic CD8+ T cells and regulatory FOXP3+ T cells was analyzed. Results: Patients with TLS had a better OS than patients without TLS, 19.4 months vs. 9.2 months (p = 0.001). Immature TLSs were more frequently associated with lymphovascular invasion and regional lymph node metastasis (p = 0.014 and p = 0.034). Mature TLSs had a higher FOXP3+ T lymphocyte density and lower CD8+/FOXP3+ ratio than immature TLSs (p = 0.029 and p = 0.013), and patients had a longer OS than patients with immature TLSs, 34.55 months vs. 15.2 months (p = 0.033). In patients with TLS-positive GC, cases with FOXP3+ T cells had a shorter OS, 12.7 months vs. 47.5 months (p < 0.001). Conclusions: The presence of FOXP3+ cells in TLS is associated with significantly shorter OS of patients with local/locally advanced GC.

Irritable bowel syndrome (IBS) and small intestinal bacterial overgrowth (SIBO) share symptoms such as abdominal pain, bloating, and altered bowel habits. Both are linked to dysbiosis and gut–brain axis dysfunction. IBS is a multifactorial disorder characterized by abnormal motility, visceral hypersensitivity, low-grade inflammation, and alterations in the microbiota. In contrast, SIBO is defined by excessive bacterial colonization of the small intestine that can mimic or worsen IBS symptoms. Gut microbes and their metabolites influence motility, immune activation, barrier integrity, and gas production; methanogen overgrowth is associated with constipation-predominant presentations, while hydrogen- and hydrogen sulfide-related pathways may contribute to diarrhea and bloating. Because recurrent or empiric antibiotic use is common—particularly in suspected SIBO—yet carries risks of resistance, microbiome disruption, and relapse, there is a strong rationale to prioritize effective non-antibiotic strategies. Accordingly, this review synthesizes current evidence on IBS/SIBO pathophysiology and microbiota interactions. It evaluates non-pharmacological interventions including dietary approaches, probiotics/prebiotics, herbal therapies, and mind–body treatments (e.g., cognitive behavioral therapy and gut-directed hypnotherapy). We emphasize an integrative framework that supports symptom control and quality of life while helping reduce unnecessary antibiotic exposure.

We studied the expression of connexin 43 (Cx43) and pannexin 1 (PANX1) in different cellular populations of the kidneys of diabetic mice and diabetic and non-diabetic patients, to evaluate their role as potential therapeutic targets in diabetic kidney disease (DKD). A combination of a low dose of streptozotocin and a high-fat diet (HFD) was used to induce a type 2 diabetes model (DM2) in mice. Kidney tissues from diabetic (n = 9) and control patients (n = 11) who underwent nephrectomy were collected. Tissues from mice and humans were processed for double immunofluorescence, using antibodies against Cx43, phosphorylated Cx43 (pCx43) or PANX1 and markers for specific cell populations: endothelium (CD31/PECAM1); pericytes/mesangium (PDGFRB); podocytes (nephrin/synaptopodin); proximal tubules and collecting ducts (aquaporin 2). The results showed a significant decrease in the expression of pCx43 in PDGFRB-immunoreactive mesangium in diabetic patients compared to the control group (p < 0.0001). This contrasted with an increase in pCx43 in pericytes of diabetic mice (p = 0.1). However, we found a general decrease in Cx43 protein expression in diabetic mouse kidneys (p < 0.05). We also found a decrease in the expression of PANX1 in endothelial cells of diabetic patients (p < 0.05) and a significant increase in PANX1 expression in cells expressing PDGFRB (p < 0.05). Expression of PANX1 in endothelium (r = -0.50; p < 0.05) and pCx43 in the mesangium (r = -0.65; p < 0.01) correlated negatively with the percentage of sclerotic glomeruli. The expression and activation of Cx43 and the expression of PANX1 are altered in distinct populations of renal cells during long-term type 2 diabetes mellitus, especially cells of the vascular wall. This may indicate their role in the pathophysiological processes of DKD. Therefore, connexin and pannexin channels could be considered as possible therapeutic targets in the prevention and treatment of diabetic kidney disease.

Pannexins are transmembrane glycoproteins that share structural and functional similarities with the gap junction proteins innexins and connexins. They play a critical role in paracrine and intracellular signalling, including purinergic signalling via the release of extracellular ATP. The role of pannexins in renal function and the pathophysiology of renal diseases is being intensely studied. However, there are no data on the subcellular localization of pannexin 1 expression in the rat kidney. We studied the distribution of pannexin 1 in the rat kidney, combining light microscopy with immunofluorescent immunohistochemistry and transmission electron microscopy with immunogold pannexin labelling. We found strong expression of pannexin in glomerular podocytes, proximal tubules and collecting ducts; moderate expression in the endothelium of glomerular and peritubular capillaries; thin descending and thick ascending limbs of the loop of Henle; and weaker pannexin 1 expression in the distal tubular epithelium. We described the detailed ultrastructural localization of pannexin 1 expression. This is the first study describing the ultrastructural distribution of pannexin 1 in the rat kidney, one of the most used preclinical models in renal physiology and pathology research. These results provide previously missing data on the precise distribution of pannexin 1 in the rat kidney, which is a prerequisite for a proper understanding of its role in renal physiology and pathophysiology.

Background/Objectives: Chronic synovitis is a hallmark of osteoarthritis (OA) progression, driving cartilage degradation via inflammatory mediators. While the MAPK signaling pathway is implicated in OA pathogenesis its activation patterns in hip synovium remain poorly characterized, and regional differences within the synovial membrane have not been systematically examined. This research aims to determine the expression of extracellular signal-regulated kinase 1/2 (ERK1/2), p38 mitogen-activated protein kinase (p38 MAPK), c-Jun N-terminal kinase (JNK), and the Epidermal Growth Factor Receptor (EGFR) in the MAPK signaling pathway in the synovial membrane of osteoarthritic hips. Methods: We compared synovial immunofluorescence expression of the aforementioned proteins in a control (CTRL) group of subjects with femoral neck fractures and a group with hip OA. Results: Higher ERK1/2 immunoexpression was detected in the intima compared with the subintima in the CTRL group (p < 0.05), and a similar distribution was observed in the OA group (p < 0.0001). The intima of the OA group exhibited a considerably greater area percentage of positive signal than the intima of the CTRL group (p < 0.01). In all groups examined, we observed that p38 MAPK expression was markedly more positive in the intima than in the subintima (p < 0.0001), but without statistically significant differences between groups. JNK and EGFR immunoexpression were higher in the intima than in the subintima across all analyzed groups, but the difference did not reach statistical significance (p > 0.05). No differences in the expression of these two markers were detected between the CTRL and OA groups (p > 0.05). Differential analysis of the GEO dataset revealed no significant differences in expression between the OA and CTRL groups in the expression of MAPK1, MAPK3, MAPK8, MAPK9, MAPK10, and MAPK11. EGFR was significantly elevated in OA compared to CTRLs in the differential analysis of the GEO dataset. Conclusions: This study provides the first comprehensive analysis of MAPK pathway activation in hip OA synovium, revealing ERK1/2 as a key player with region-specific upregulation in the synovial intima. Combined with elevated EGFR expression, these findings suggest potential therapeutic targets for hip OA synovitis. The discordance between protein and mRNA levels for ERK1/2 indicates post-transcriptional regulation, warranting further investigation into phosphorylation status and functional activation. Our results support the development of targeted interventions for hip OA, a condition with limited treatment options beyond joint replacement.

Background/Objectives: The meninges, the protective membranes covering the central nervous system, undergo complex developmental processes that are critical for CNS integrity and function. Connexin 37 (Cx37) and 40 (Cx40), members of the connexin family of gap junction proteins, have been implicated in various physiological and pathological processes. They play a critical role in cell–cell communication. The aim of our study was to investigate the expression of connexins Cx37, Cx40, and Panx1 in the meninges of both human and murine models (yotari and wild type) at the 6th week/E13.5 and 8th week/E15.5 of developmental stages. Methods: Human embryonic tissues (6th–8th week, n = 4 for the 6th week and n = 4 for the 8th week) and mouse embryos (yotari Dab1−/− and wild type, E13.5–E15.5) were collected and fixed in 4% paraformaldehyde. Paraffin sections were stained for Cx37, Cx40, and Panx1 using immunofluorescence. Images were analyzed in ImageJ, and statistical comparisons were performed using one-way ANOVA with Tukey’s post hoc test (p < 0.05). Results: Cx37 was consistently expressed across all developmental stages, with the highest threshold area percentage observed at E13.5 and E15.5 in murine leptomeninges, demonstrating statistically significant differences compared to controls (p < 0.05) and notably from corresponding human stages (p < 0.001). Strong Cx37 staining intensity at E13.5 was noted in both wild-type and yot mice, while human leptomeninges displayed mild staining at the 6th week of development. In contrast, both human and murine pachymeninges exhibited moderate Cx37 expression. Additionally, the expression of Cx37 in wild-type mice surpassed that of human samples at both E13.5 and E15.5 stages (p < 0.01 and p < 0.001, respectively). For the developing dura mater, Cx37 expression peaked at E15.5 in yot mice, significantly different from both wild-type and human dura mater (p < 0.01 and p < 0.05). Cx40 expression was highest in the leptomeninges at E15.5. Panx1 was similarly expressed across stages, with the highest threshold area percent observed in wild-type leptomeninges and pachymeninges at E15.5, showing significant differences compared to yot mice and human samples (p < 0.05). Both leptomeninges and pachymeninges exhibited mild Panx1 staining at E13.5, while stronger staining was observed at E15.5 in murine samples, contrasting with mild intensity in human counterparts. Conclusions: These findings highlight the implications of Dab1 deficiency for the expression of gap junction proteins during meninges development, implicating their importance in intercellular communication that is essential for normal meningeal and neurodevelopmental processes.

Simple Summary Eye cancers can damage vision and, in some cases, threaten life. Retinoblastoma mainly affects children, while uveal melanoma is the most common eye cancer in adults. Doctors need better ways to judge how aggressive these tumors are and to find new treatment targets. We examined five proteins that help cells handle nutrients and signals, Megalin, Cubilin, Caveolin-1, GIPC1, and DAB2IP, in normal eye tissue, retinoblastoma, and different forms of choroidal melanoma. Using fluorescent staining, we measured the amount of each protein present, then compared our results with publicly available gene data and patient survival information. Our goal was to learn whether changes in these proteins track with tumor type and outcome. These findings may support the development of future tools for diagnosis, risk prediction, and therapy design in eye cancer.

The heart’s relentless contractile activity depends critically on mitochondrial function to meet its extraordinary bioenergetic demands. Mitochondria, through oxidative phosphorylation, not only supply ATP but also regulate metabolism, calcium homeostasis, and apoptotic signaling, ensuring cardiomyocyte viability and cardiac function. Mitochondrial dysfunction is a hallmark of cardiomyopathies and heart failure, characterized by impaired oxidative phosphorylation, excessive production of reactive oxygen species (ROS), dysregulated calcium handling, and disturbances in mitochondrial dynamics and mitophagy. These defects culminate in energetic insufficiency, cellular injury, and cardiomyocyte death, driving heart disease progression. Diverse cardiomyopathy phenotypes exhibit distinct mitochondrial pathologies, from acute ischemia-induced mitochondrial collapse to chronic remodeling seen in dilated, hypertrophic, restrictive, and primary mitochondrial cardiomyopathies. Mitochondria also orchestrate cell death and inflammatory pathways that worsen cardiac dysfunction. Therapeutic strategies targeting mitochondrial dysfunction, including antioxidants, modulators of mitochondrial biogenesis, metabolic therapies, and innovative approaches such as mitochondrial transplantation, show promise but face challenges in clinical translation. Advances in biomarker discovery and personalized medicine approaches hold promise for optimizing mitochondrial-targeted therapies. Unlike previous reviews that examined these pathways or interventions individually, this work summarizes insights into mechanisms with emerging therapeutic strategies, such as SGLT2 inhibition in HFpEF, NAD+ repletion, mitochondrial transplantation, and biomarker-driven precision medicine, into a unified synthesis. This framework underscores the novel contribution of linking basic mitochondrial biology to translational and clinical opportunities in cardiomyopathy and heart failure. This review synthesizes the current understanding of mitochondrial biology in cardiac health and disease, delineates the molecular mechanisms underpinning mitochondrial dysfunction in cardiomyopathy and heart failure, and explores emerging therapeutic avenues aimed at restoring mitochondrial integrity and improving clinical outcomes in cardiac patients.

Simple Summary Advanced gastric cancer is generally associated with a poor prognosis. Stroma AReactive Invasive Front Area (SARIFA) is a recently recognized aggressive histological feature, defined as five tumor cells in direct contact with adipocytes within perigastric, submucosal, or perivascular adipose tissue. The aim of our retrospective study was to evaluate the correlation of SARIFA with pathohistological variables and its impact on overall survival. A cohort of 102 Croatian patients with locally advanced gastric cancer was analyzed, and a significant association between SARIFA and nodal metastases as well as perineural invasion was observed. Patients with both lymphovascular invasion and SARIFA had a significantly higher proportion of affected lymph nodes. They also exhibited a shorter, though not statistically significant, overall survival compared with patients with one or neither of these factors (median 9.2 vs. 16.1 months). A positive SARIFA status may serve as a biomarker of invasiveness and an additional prognostic risk factor. Abstract Background/Objectives: Advanced gastric cancer usually has an unfavorable prognosis. Stroma AReactive Invasion Front Area (SARIFA) is a newly recognized biomarker of aggressiveness, easily recognized as five tumor cells in direct contact with adipocytes in perigastric, submucosal, and perivascular adipose tissue. We investigated this phenomenon and correlated it with other pathohistological variables. Material and Methods: The sample includes 102 Croatian patients with locally advanced gastric cancer, who underwent total gastrectomy/lymphadenectomy between 2012–2018 and in 2023 at University Hospital Split, Croatia, and had pathological stage pT3 or pT4. Representative histological specimens were analyzed for SARIFA, and results were compared with other variables and overall survival. External validation and gene expression analysis of CD36 and FABP4 were performed using the TCGA-STAD cohort. Results: SARIFA was significantly associated with positive pN status (p = 0.009) and perineural invasion (p = 0.043). Patients with SARIFA had a more than fivefold increased risk of nodal involvement (OR = 6.35; 95% CI: 1.35–29.84; p = 0.019). Lymphovascular invasion (LVI) was associated with nodal disease (OR = 4.39; 95% CI: 1.194–16.143; p = 0.026), and SARIFA was marginally associated (OR = 4.886; 95% CI: 0.985–24.241; p = 0.052). Patients who had both LVI and SARIFA had a higher proportion of affected lymph nodes (p = 0.009). SARIFA status did not significantly affect overall survival. Gene expression analysis showed a significant increase in CD36 expression, while FABP4 expression was elevated but not statistically significant, in SARIFA-positive cases. Conclusions: SARIFA could be used as a marker for invasiveness and further investigated due to its predictive potential.

Background/Objectives: Hip osteoarthritis (HOA) is a progressive joint disease characterized by cartilage loss, subchondral bone changes, and synovial inflammation. While tumor necrosis factor receptor 1 (TNFR1), interleukin-6 (IL-6), and transforming growth factor-beta 1 (TGF-β1) are recognized as key mediators of joint pathology, their compartment-specific expression in the human hip synovium remains insufficiently characterized. Therefore, we aimed to investigate their localization and expression in the intimal and subintimal compartments of synovial tissue in patients with HOA compared to controls (CTRL). Methods: Synovial membrane samples were obtained from 19 patients with primary HOA undergoing total hip arthroplasty and 10 CTRL subjects undergoing arthroplasty for acute femoral neck fracture without HOA. Specimens were processed for hematoxylin and eosin (H&E) and immunofluorescence staining. Expression of TNFR1, IL-6, and TGF-β1 was quantified in the intima and subintima using ImageJ analysis. Group differences were assessed using two-way Analysis of variance (ANOVA) with Tukey’s test when assumptions were met; for heteroscedastic outcomes we applied Brown–Forsythe ANOVA with Dunnett’s T3 multiple comparisons. Results: Histological analysis confirmed synovitis in HOA samples, with intimal hyperplasia and mononuclear infiltration. IL-6 was significantly upregulated in the intima of HOA synovium compared with CTRLs, while subintimal expression remained unchanged. In contrast, TGF-β1 expression was reduced in the HOA intima, eliminating the normal intima–subintima gradient. For TNFR1, the within-HOA contrast (int > sub) was significant, whereas the intimal HOA vs. CTRL comparison showed a non-significant trend. Transcriptomic analysis supported IL-6 upregulation, while TNFR1 and TGF-β1 did not reach statistical significance at the mRNA level in an orthogonal, non-hip (knee-predominant) dataset. Conclusions: These findings demonstrate compartment-specific cytokine dysregulation in HOA, with increased intimal TNFR1 and IL-6 alongside reduced intimal TGF-β1. The synovial lining emerges as a dominant site of inflammatory signaling, underscoring its importance in disease progression.

The kidney’s intricate physiology relies on finely tuned gene regulatory networks that coordinate cellular responses to metabolic, inflammatory, and fibrotic stress. Beyond protein-coding transcripts, non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), have emerged as pivotal regulators of renal biology. By modulating transcriptional, post-transcriptional, and epigenetic pathways, ncRNAs govern podocyte integrity, tubular adaptation, intercellular signaling, and immune activation. Dysregulation of these networks is now recognized as a hallmark of major kidney diseases, ranging from diabetic nephropathy and acute kidney injury to chronic kidney disease, glomerulopathies, and polycystic kidney disease. Mechanistic studies have revealed how pathogenic ncRNAs drive apoptosis, inflammation, fibrosis, and cystic remodeling, while protective ncRNAs mitigate these processes, highlighting their dual roles as both disease mediators and therapeutic targets. The exceptional stability of ncRNAs in urine, plasma, and exosomes further positions them as minimally invasive biomarkers with diagnostic and prognostic value. Translational advances include anti-miR and mimic-based therapies (e.g., lademirsen targeting miR-21, miR-29 mimics, anti-miR-17 oligonucleotides), alongside lncRNA silencing strategies, although challenges in delivery, safety, and redundancy remain significant. This review integrates molecular mechanisms with translational perspectives, providing a comprehensive synthesis of how ncRNAs shape renal pathophysiology. By bridging mechanistic insights with emerging diagnostic and therapeutic applications, we highlight the potential of ncRNAs to transform nephrology, paving the way for biomarker-driven precision medicine and novel interventions aimed at intercepting kidney injury at its regulatory roots. In clinical terms, ncRNA-based biomarkers and therapeutics promise earlier detection, more precise risk stratification, and individualized treatment selection within precision nephrology.

Background and objectives: Melanocytic nevi are among the most common skin lesions, yet their relationship with the peripheral nervous system has remained understudied. Given the neural crest origin of melanocytes and Schwann cells, and the neurotrophic signaling capabilities of pigment cells, this study aimed to investigate the density of nerve fibers within nevi and assess how it varies with respect to histological subtype and anatomical location. Materials and Methods: A total of 90 nevi were analyzed, including junctional, compound, and intradermal types, distributed across the head, trunk, and limbs. Immunofluorescence staining for the pan-neuronal marker PGP 9.5 and for CGRP were performed and nerve fiber density was quantified. Statistical evaluation using two-way ANOVA revealed that both nevus type and anatomical site significantly influenced the degree of total innervation. Results: Junctional nevi demonstrated the highest total nerve fiber density, significantly exceeding that of compound and intradermal nevi. Likewise, nevi located on the head exhibited a significantly greater density of PGP 9.5-positive nerve fibers compared to those on the trunk and limbs. No significant correlation was observed between nevus type and location, suggesting that both factors contribute independently to the differences in innervation. CGRP-positive innervation was uniform regardless of the histological type of nevus and anatomical location. Conclusions: These findings likely reflect the facts that junctional nevi reside at the dermo-epidermal junction, where nerve fibers are most abundant, while the skin of the head and neck is well known to be more richly innervated than other regions. In contrast, analysis of CGRP-positive fibers suggests that the heterogeneity detected with PGP 9.5 is primarily driven by other neuronal populations. The results support the hypothesis of a dynamic relationship between nevi and the peripheral nervous system, potentially mediated by neurotrophic factors. Understanding this interaction may provide insight into nevus biology, sensory symptoms reported in some lesions, and the evolving role of nerves in the tumor microenvironment.