BCL2 and B-cell chronic lymphocytic leukemia: A recent analysis of CLL patients who progressed on venetoclax found that 7 of the 15 patients developed a mutation, Gly101Val, in BCL2, which decreases the affinity of BCL2 for venetoclax by overcrowding the BH3 binding groove, thereby preventing venetoclax from displacing the pro-apoptotic proteins [Table 2][14-18].