CADM2 (cell adhesion molecule 2) is a multifunctional protein that serves as a tumor suppressor and regulator of cellular behavior across diverse biological contexts. (a) Primary function: CADM2 functions as a cell adhesion molecule involved in maintaining cell-cell adhesion and cellular polarity 12. The protein plays crucial roles in neurotransmitter signaling, being involved in glutamate signaling and GABA transport pathways, particularly in nervous system function 3. (b) Mechanism: CADM2 exerts its effects through regulation of epithelial-mesenchymal transition (EMT) processes and cell cycle control. Overexpression leads to decreased expression of cell cycle regulators including cyclin D1, cyclin E, CDK2, and CDK4, while affecting EMT markers like E-cadherin and β-catenin 12. (c) Disease relevance: Genetic variants in CADM2 are associated with multiple conditions including glioma, irritable bowel syndrome, endometriosis, and various behavioral traits such as risk-taking behavior, mood disorders, and cognitive function 14253. CADM2 is consistently downregulated in malignant tissues including gliomas and endometriosis 12. (d) Clinical significance: CADM2 represents a potential therapeutic target, with its tumor suppressor functions making it relevant for cancer treatment strategies and its genetic variants serving as biomarkers for behavioral and metabolic traits 16.