MCL1 and neoplasm: However, the levels of anti-apoptotic machinery members (BCL-2, BCL-XL and MCL-1) were not dramatically affected (Figure 3B and 3C and Supplementary Figure S1) indicating the strong tumor cell inhibition and induction of apoptosis in EC cells by ABT263 may be due to other mechanisms in addition to its canonical anti-BCL2 family.