ABT-199 in combination with chemotherapeutic agents in human T-ALL cell lines. The effect of monotherapy or combination therapy on the viability of T-ALL cell lines is visualized. Cell viability is expressed relative to cells treated with dimethylsulfoxide and the average and standard deviation of 2 independent experiments is plotted for each combination. Combination of ABT-199 with doxorubicin (A) or l-asparaginase (B) in the T-ALL cell lines LOUCY, JURKAT, and ALL-SIL. (C) Combination of ABT-199 and dexamethasone is only shown for the LOUCY cell line. The combination index (CI) shown represents the average of the CIs at the ED50, ED75, and ED90 effect levels for each experiment. 0.9 < CI < 1.1: nearly additive; 0.85 < CI < 0.9: slight synergism; 0.7 < CI < 0.85: moderate synergism; 0.3 < CI < 0.7: synergism; 0.1 < CI < 0.3: strong synergism; CI < 0.1: very strong synergism.