Human CD95, also known as Fas or APO-1, is a cell-surface death receptor belonging to the tumor necrosis factor receptor (TNFR) superfamily. CD95 plays a central role in the regulation of apoptosis and immune homeostasis. Binding of CD95 ligand (CD95L/FasL) to CD95 induces receptor oligomerization and formation of the death-inducing signaling complex (DISC), which activates downstream caspases and initiates the extrinsic apoptotic pathway.

Human CD95 antibodies with blocking or activating activity are valuable tools for investigating the biological functions of the CD95/CD95L signaling pathway. Blocking antibodies bind to CD95 and inhibit its interaction with CD95L, thereby reducing or preventing CD95-mediated signaling and apoptosis. In contrast, activating antibodies bind to CD95 and promote receptor clustering or signaling, thereby mimicking receptor stimulation and inducing downstream apoptotic pathways.

These antibodies are widely used in research on apoptosis, immune-cell homeostasis, immune tolerance, inflammation, and cancer biology. Blocking antibodies can be used to investigate the effects of inhibiting CD95 signaling, while activating antibodies provide a useful approach for studying CD95-mediated apoptosis and downstream signal transduction. The biological activity and optimal experimental conditions depend on the antibody clone, epitope, valency, and assay system.