essential mediator of p53-dependent and independent apoptosis. Binds to anti-apoptotic Bcl-2 family members to induce mitochondrial dysfunction and caspase activation. Interacts with BCL2, BCL2L1, MCL1 and BCL2A1. Functions by promoting partial unfolding of BCL2L1 and dissociation of BCL2L1 from p53. Regulates ER stress-induced neuronal apoptosis. Induced by DNA damage, glucocorticoid treatment, growth factor deprivation and p53. Ubiquitously expressed. Ubiquitously expressed. Belongs to the Bcl-2 family, BH3-only pro-apoptotic subclass. Four isoforms of the human protein are apparently produced by alternative splicing. Note: This description may include information from UniProtKB.