MCL1 and leukemia: CG-806 demonstrated much more pronounced anti-proliferative than pro-apoptotic effects, accompanied by only marginal inhibition of Bcl-2, Bcl-xL, and Mcl-1 as well in most of the tested leukemia cell lines, even upregulated the anti-apoptotic protein Mcl-1 in Ba/F3-FLT3-WT and ITD mutant cells (Fig. 2C).