Antiapoptotic protein which protects cells uniquely from Fas-induced apoptosis. Regulates Fas-mediated apoptosis in neurons by interfering with caspase-8 activation. Plays a role in cerebellar development by affecting cerebellar size, internal granular layer (IGL) thickness, and Purkinje cell (PC) development (By similarity). Interacts with FAS/TNFRSF6 and BAX. Expressed at high levels on dendrites and to a lesser extent on the soma and axons of neurons in various regions of brain. Low expression was detected in brain and spinal cord at birth, increasing with age to highest levels in postnatal days 60 (P60). Belongs to the BI1 family. LFG subfamily.