Fig 1: The synergistic pro-apoptotic effect of the combination of ABT-199 and metformin is achieved by reducing ABT-199 induced compensatory increase of Mcl-1. The ATP production was measured with ATP Assay Kit by Biotek Synergy LX after 48 hours treatment of ABT-199 and metformin in KG-1 (A) and Kasumi-1 (B). The level of Mcl-1, Bcl-2, BCL-xl proteins were detected using western blot after ABT-199, metformin, ABT-199/metformin treated for 48 hours in THP-1 (C) and KG-1 cells (E). The statistical result of Mcl-1 in the (C) and (E) graph results was shown in (D) and (F). (*P < 0.05; ** P < 0.01; *** P < 0.001). THP-1 cells were treated with ABT-199, S63845 and metformin alone or in combination, the cell viability was measured and the inhibition rate was calculated. (* P < 0.05; ** P < 0.01; *** P < 0.001).