Midostaurin and its metabolites inhibit a variety of kinases.^ae1 and e2 are 2 epimers of the previously reported metabolite CGP52421. ^bApparent 50% inhibitory concentration for 1:1 mixture. Red denotes an 50% inhibitory concentration <0.1 μM; orange, 0.1 to <0.25 μM; yellow, 0.25 to <0.5 μM; green, 0.5 to <1 μM; blue, 1 to 10 μM; and purple, >10 μM.