AML cases with mutated Flt3 (Flt3-ITD) are very sensitive to MI219. MI219 IC₅₀ values categorized by (1) p53 mutation status, (2) presence of Flt3-ITD, and (3) all others. Differences in the mean IC₅₀ value between Flt3-ITD⁺ and all other cases are significant (P = .02).