Anti-apoptotic protein which can inhibit apoptosis induced by intrinsic and extrinsic apoptotic stimuli. Can modulate both capacitative Ca2+ entry and inositol 1,4,5-trisphosphate (IP3)-mediated Ca2+ release. {ECO:0000269|PubMed:17319741, ECO:0000269|PubMed:19553469}. This is the function of TMBIM4 (transmembrane BAX inhibitor motif containing 4, ENSG00000155957).