MAMDC4 (MAM domain containing 4) is an endosomal membrane protein primarily involved in regulating intestinal epithelial homeostasis and receptor transport. During postnatal intestinal development, MAMDC4 localizes to the apical endocytic complex of villus enterocytes and is essential for normal proliferation 1. The protein functions as an endosomal regulator that mediates cross-talk between YAP and β-catenin signaling pathways through non-canonical interactions involving AMOT, thereby fine-tuning transcriptional activity critical for intestinal stem cell proliferation and differentiation 2. MAMDC4 expression is dynamically regulated during postnatal development and is significantly influenced by intestinal bacterial colonization, with different bacterial species showing distinct effects on its maintenance 3. Clinically, MAMDC4 variants have been implicated in genetic disease susceptibility. A rare out-of-frame MAMDC4 deletion was identified in a multigenerational family with axial spondyloarthritis, suggesting disease pathogenesis through RNA-mediated decay 4. Additionally, MAMDC4 belongs to a subset of genes enriched in rare variants with similarities to disease-causing variants, making it a strong candidate for disease discovery in sequencing studies 5. MAMDC4 expression changes have also been associated with cardiovascular and cancer pathologies, showing upregulation in Western diet-associated atherosclerosis 6 and altered expression in prostate cancer contexts 78.