Cells dependent on JAK3 mutants are sensitive to JAK3 and JAK1 inhibition. (A-B) Relative proliferation of Ba/F3 cells transformed by JAK3 mutants or FLT3 ITD or wild-type Ba/F3 cells stimulated with IL3 after treatment with tofacitinib or ruxolitinib, respectively. Proliferation was compared with proliferation of cells after vehicle (DMSO) treatment. Full dose-response curves for all JAK3 mutants are shown in the supplemental material (supplemental Figures 3-6). (C-D) Western blot analysis of Ba/F3 cells expressing JAK3 mutants after 90 minutes of treatment with tofacitinib or ruxolitinib.