FLT3 and leukemia: We compared the protective effect of unfractionated CM, S100, and P100 fractions on the viability of two leukemia cell lines: MOLM14 (FLT3 ITD+ AML) and K562 (CML), in the presence of their respective TKIs, quizartinib (AC220, a highly selective and potent inhibitor [Zarrinkar et al., 2009]) and imatinib (Figure 1A and B).