CD316 is an approximately 63 kDa transmembrane glycoprotein, which forms stable complexes with CD9, as well as with CD81. It seems that CD316 participates in regulation of cell polarity and motility, in cell proliferation, oocyte fertilization and tumor cell metastasis. It is expressed mainly by lymphocytes, NK cells and in a broad range of tissues, and associates with actin cytoskeleton.