CD107b, also known as lysosome-associated membrane protein 2 （LAMP-2）, is a highly glycosylated type I transmembrane protein with a molecular weight of approximately 105–120 kDa. It is primarily located in the lysosomal/endosomal membranes of nearly all cells and can be transiently expressed on the surface of activated platelets, activated lymphocytes, and some tumor cell lines. LAMP-2 plays crucial roles in various cellular processes, including cell adhesion, cellular homeostasis, autophagocytosis, antigen presentation, and protection of the lysosome. Additionally, it may be involved in tumor cell metastasis by mediating adhesion to vascular endothelium.