CDH3 (cadherin 3) is a calcium-dependent cell adhesion protein that mediates homophilic cell-cell interactions through adherens junctions 1. The gene encodes P-cadherin, which functions in tissue integrity, cell localization, and cell sorting through β-catenin binding and catenin complex assembly. In normal tissues, CDH3 plays regulatory roles in retinal homeostasis, hair follicle maturation, and keratinization 2. Functionally, CDH3 can suppress hepatocellular carcinoma cell growth and migration via GSK-3β signaling when upregulated by the tumor suppressor KLF4 3. However, CDH3 is frequently elevated in multiple cancer types with pathological consequences. In lung adenocarcinoma, high CDH3 expression promotes epithelial-mesenchymal transition, glycolysis, hypoxia, tumor-associated macrophage infiltration, and immunosuppression, correlating with poor survival and reduced immunotherapy response 4. Similarly, CDH3 overexpression in colorectal cancer associates with metastasis, poor prognosis, and altered immune infiltration 5. CDH3 is uniformly expressed on pancreatic ductal adenocarcinoma cells, enabling targeted therapy with bispecific antibodies that simultaneously engage CDH3 and death receptors 6. Clinically, CDH3 mutations are associated with rare inherited disorders including ectodermal dysplasia with macular dystrophy 2 and superior canal dehiscence syndrome 1. CDH3 represents a promising biomarker and therapeutic target for cancer management.