CD151 is a tetraspanin protein that functions primarily in cell adhesion, migration, and inflammatory regulation. As a transmembrane protein, CD151 interacts with integrins (particularly α3β1 and α6β4) through palmitoylation to regulate cell-cell communication and wound healing 1. Beyond adhesion, CD151 maintains endolysosomal protein quality by docking VCP/p97 onto endolysosomes, controlling exosome biogenesis and limiting the release of proinflammatory cytokines such as angiopoietin-2 2. This protein quality control function prevents vascular inflammation and supports endothelial integrity during sepsis and viral infection 2. In cancer biology, CD151 plays complex roles depending on context. High CD151 expression promotes hepatocellular carcinoma progression by enriching migrasomes—membrane vesicles that enhance tumor cell invasion and angiogenesis through VEGF signaling 3. CD151 also functions as a prognostic biomarker in senescent cancer-associated fibroblasts that promote cancer stemness in HCC 4. Additionally, CD151 supports viral infections: it contributes to human papillomavirus entry through integrin-dependent mechanisms 5 and participates in organizing tetraspanin-enriched microdomains that regulate cell contact-independent intercellular communication via exosomes 6. Mutations in CD151 cause epidermolysis bullosa simplex with nephropathy and deafness, highlighting its essential role in maintaining tissue integrity and basement membrane stability.