Cells were seeded in 96-well microplates 1 day before the start of treatment. At the onset of the experiment, growth medium containing inhibitors was added to the cells with final concentrations as indicated in the figures. Control cells were treated with similar amount of vehicle as the treated cultures (0.1% DMSO). Cell viability was measured after 48 hours of treatment using the ATPlite 1step Luminescence Assay System (PerkinElmer Life Sciences) or CellTiter-Glo Luminescent Cell Viability Assay (Promega) according to the manufacturer’s instructions. Luminescence was measured using an EnSpire 2300 Multilabel Reader (PerkinElmer Life Sciences) or a Tecan infinite M200 PRO multimode microplate reader. Three independent biological experiments, each prepared in triplicate or quadruplicate for each concentration, were performed with reproducible results. An IC50 value for each inhibitor was determined corresponding to the concentration giving 50% reduction in cell viability. The IC50 values were derived from a five-parameter nonlinear curve fitting using GraphPad Prism software, and the experimentally used IC50 concentrations were within the 95% CI. The combination effect of LDK378 and dasatinib or KD025 (fig. S6, C and D) was determined using the Bliss independence model to calculate interaction scores (ΔI) as previously described (71), and for positive ΔI values, any two-drug combinations were considered synergistic.