Retards apoptosis induced by IL-3 deprivation. May function in the response of hemopoietic cells to external signals and in maintaining endothelial survival during infection (By similarity). Can inhibit apoptosis induced by serum starvation in the mammary epithelial cell line HC11 (By similarity). {ECO:0000250, ECO:0000250|UniProtKB:Q07440}. This is the function of BCL2A1 (BCL2 related protein A1, Ensembl gene identifier ENSG00000140379).