APO-1/Fas (Fas receptor, APO 1 cell surface antigen, Apo-1 Fas, Apoptosis antigen 1, Apoptosis mediating surface antigen FAS, CD95 antigen, Tumor necrosis factor receptor superfamily 6)

APO-1/Fas (48 kDa), a member of the TNF/NGF receptor superfamily, is a glycosylated surface protein containing a single transmembrane region. APO-1 is expressed on a variety of human B and T cell lines, on many different tumor cells and on various normal human tissues. The tissue distribution of APO-1 and of the APO-1 ligand suggests that the APO-1 receptor/ligand system plays an important role in various aspects of mammalian development and especially in the homeostasis of the immune system.