VCAM1 (vascular cell adhesion molecule 1) is a cell surface glycoprotein that serves multiple critical functions in vascular biology, immune regulation, and disease pathogenesis. Its primary function involves mediating cell adhesion between endothelial cells and immune cells through integrin interactions 1. VCAM1 facilitates leukocyte recruitment and transendothelial migration during inflammatory responses by interacting with integrin subunit alpha 4 (ITGA4) and activating NF-κB signaling pathways 1. Beyond vascular biology, VCAM1 functions as an immune checkpoint molecule, providing 'don't-eat-me' signals to hematopoietic and leukemic stem cells through interactions with MHC class-I presentation and PIR-B receptors on phagocytes 2. In the central nervous system, VCAM1 directs microglial chemotaxis toward amyloid-beta plaques by sensing plaque-associated ApoE, contributing to amyloid clearance 3. VCAM1 expression is dysregulated in multiple diseases, including gastric cancer where H3K18 lactylation promotes its transcription and subsequent AKT-mTOR pathway activation 4, sepsis-related acute lung injury through endothelial cell-derived extracellular vesicles 1, and chr1 kidney disease where inflammatory tubular cells express VCAM1 in fibrotic niches 5. Therapeutically, VCAM1 represents a promising target for treating age-related neurodegeneration, cancer progression, and inflammatory diseases.