CDH19 (cadherin 19) is a calcium-dependent cell adhesion protein located on chromosome 18-q23 that mediates homophilic cell-cell interactions through adherens junctions 1. The protein functions as a classical cadherin involved in cell-cell adhesion, cell morphogenesis, and junction assembly 1. CDH19 is expressed in diverse cell types including Schwann cells, where it serves as a marker of mature peripheral nervous system cells 2. In cancer contexts, CDH19 demonstrates context-dependent roles. In gastric cancer, CDH19 is upregulated and its knockdown increases intracellular iron and reactive oxygen species, inhibiting cell proliferation and migration through effects on ferroptosis-related genes ACSL4 and GPX4 3. Conversely, in cervical carcinoma, CDH19 is downregulated; overexpression suppresses cell proliferation and AKT/NF-κB signaling activation, with high CDH19 expression correlating with improved survival 4. In bladder cancer and colorectal cancer, CDH19 functions as a prognostic biomarker associated with disease progression 5, 6. Additionally, CDH19 genetic variants are associated with white matter microstructure in aging and Alzheimer's disease, with CDH19 expression enriched in oligodendrocytes 7. These findings establish CDH19 as a multifunctional adhesion protein with disease-specific therapeutic potential across multiple cancer types and neurological conditions.