PTPN23 is a protein tyrosine phosphatase that functions as a multifaceted regulator of endosomal trafficking and cell survival. Primarily, PTPN23 coordinates with ESCRT-I complex machinery to sort ubiquitinated cargos into multivesicular bodies for degradation 12. Recent evidence reveals that PTPN23-dependent ESCRT machinery functions as a cell death checkpoint, regulating endosomal accumulation of death receptors and toll-like receptors to restrain apoptotic, necroptotic, and pyroptotic pathways 3. PTPN23 also mediates microautophagy of ubiquitylated tau aggregates through interaction with ESCRT-I and ESCRT-III complexes 4, while facilitating cardiac T-tubule formation by promoting dystrophin-glycoprotein complex assembly at costameres 5. Clinically, PTPN23 mutations cause neurodevelopmental disorders with structural brain anomalies, seizures, and spasticity 67. Loss of PTPN23 promotes proliferation and epithelial-to-mesenchymal transition in colorectal cancer through enhanced EGF signaling 8, establishing PTPN23 as a tumor suppressor 9. Additionally, PTPN23 activates PI3KC2α signaling to support BRAF-mutant melanoma cell survival, making it a therapeutic vulnerability 10. These findings position PTPN23 as critical for developmental integrity, cancer suppression, and cellular quality control.