Fas / APO1 (CD95) is an important member of the tumour necrosis factor (TNF) superfamily involved in membrane-mediated apoptosis. Ligation of Fas by Fas Ligand or an anti Fas cross linking antibody, triggers activation of the caspase cascade. Functional impairment of the Fas / Fas Ligand system is associated with the development and progression of malignancies. Fas gene mutations have been suggested to have a role in testicular germ cell tumours. Tumour cells frequently exhibit de novo expression of Fas Ligand, which plays a significant role in local tissue destruction, metastatic spread, and immune escape of the tumor cells. The apoptosis of lymphocytes, which occurs in autoimmune diseases, is usually induced by the Fas/Fas Ligand system.

Cell Membrane (single-pass type II membrane protein) and Secreted