FLT3 and acute megakaryoblastic leukemia in down syndrome: Here, we report the results of a large-scale screen of human cancer cell lines representing two high-risk subtypes of pediatric AML including MLL rearranged (MLLr) with or without a co-occurring FLT3-internal tandem duplication (FLT3-ITD) mutation and non-Down syndrome acute megakaryoblastic leukemia (AMKL)2–4.