The difference in the susceptibility of D-10-0021 MG, DM440, and SUM159-R113 cells to the 9.2.27-PE38KDEL, ABT combinations impelled us to examine the role of selected prosurvival (Bcl-xL and Mcl-1) and proapoptotic (Bim and Bax) Bcl-2 members in potentiating tumor cell death (S4 Fig). This evidence concerns the gene MCL1 and neoplasm.