Analysis of BCL-2, BCL-XL, and MCL-1 protein levels in primary AML samples (N = 577) showed that MCL-1, BCL-2, and BCL-XL exhibited variable protein expression levels, within and across differentiation stages (French-American-British [FAB] classification subgroups), as well as across different cytogenetic and molecular defined subgroups (178). Here, BCL2 is linked to acute myeloid leukemia.