CD63

CD63 is a lysosomal membrane glycoprotein belonging to the transmembrane 4 superfamily. It can promote the formation of exosomes and participate in cell adhesion and migration. The initial research indicated that the expression level of CD63 is down-regulated with the pathological progression and lymph node metastasis of melanoma, speculated that it can bind to integrin β1 and interact with extracellular matrix (ECM) to inhibit the motility and ECM degradation function of cancer cells. Meanwhile, CD63 in esophageal cancer can inhibit metastasis by regulating the occurrence of epithelial-mesenchymal transition (EMT). Low expression of CD63 is also considered as an indicator of poor prognosis in lung adenocarcinoma patients. However, CD63 positive patients with gastric cancer, pancreatic cancer and ovarian cancer have worse prognosis, which may be because CD63 participates in invasion and immune escape of tumors after binding to tissue inhibitor of metalloproteinases-1 (TIMP1). In addition, CD63 in breast cancer can promote cell proliferation by activating YAP pathway. In summary, the specific mechanism of CD63 in different tumors still needs further research.