BCL2L1 and acute promyelocytic leukemia: The importance of BCL2 family members in AML is indicated by the expression of BCL2, BCL2L12, BCL-XL, and BAD in leukemic CD34+ cells, whereas normal promyelocytes (in non-APL AML cases) (CD34-CD33+) lack BCL2 and BCL-XL expression.