FLT3 and leukemia: As for R/R AML, or carrying FLT3 mutation, homoharringtonine usually is combined with other therapeutic agents, for instance, homoharringtonine added into venetoclax and cytarabine yielded a CR of 70.8% (19), into DAC-HAA for pediatric R/R AML yielded CR of 77.4% (20), and into FLT3-mutation inhibitor yielded a inhibitory effect in leukemia cell lines (21, 22).