Promotes cell survival. Blocks dexamethasone-induced apoptosis. Mediates survival of postmitotic Sertoli cells by suppressing death-promoting activity of BAX. Expressed in a wide range of tissues with highest levels in brain, spinal cord, testis, pancreas, heart, spleen and mammary glands. Moderate levels found in thymus, ovary and small intestine. Not detected in salivary gland, muscle or liver. Also expressed in cell lines of myeloid, fibroblast and epithelial origin. Not detected in most lymphoid cell lines. Belongs to the Bcl-2 family. 2 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.