Outgrowth of resistant cells in the presence of inhibitor combinations. (A) Number of wells with resistant growth in the presence of imatinib mesylate 1 μM and 2 μM combined with graded concentrations of nilotinib (50 nM, 500 nM, 1000 nM, and 2000 nM). (B) Number of wells with resistant growth in the presence of imatinib mesylate 1 μM and 2 μM combined with graded concentrations of dasatinib (5 nM, 10 nM, 25 nM, and 100 nM). (C) Number of wells with resistant growth in the presence of graded concentrations of nilotinib (50 nM, 500 nM, 1000 nM, and 2000 nM) and dasatinib (5 nM, 10 nM, 25 nM, and 100 nM).