CD146 is a membrane glycoprotein that belongs to the immunoglobulin superfamily and functions as a Ca2+-independent cell adhesion molecule. It mediates interactions between cells and between cells and the extracellular matrix, promoting the adhesion and proliferation of endothelial cells, and is involved in tumor angiogenesis and metastasis. CD146 is highly expressed in various malignant tumor tissues, where it facilitates the migration and spread of tumor cells, suggesting its potential role in tumor invasion and metastasis. It can also serve as a reference marker for the prognosis of cancer patients. Moreover, CD146 functions not only as an adhesion molecule but also as a cell membrane receptor that mediates signaling pathways involved in the development of tumors and inflammation. Its roles extend beyond cell adhesion to include signal transduction.