BCL2 and acute myeloid leukemia: It remains to be determined clinically whether some cases of AML with high BCL-XL expression (putatively erythroleukemia or megakaryoblastic lineage expression of BCL-XL) may be more resistant to the proposed combination of venetoclax and alvocidib, and thus benefit more from dual BCL-2 and BCL-XL inhibition (i.e. navitoclax/ABT-737/ABT-263) alone or combined with alvocidib.