After inhibition of autophagy, MSCs-mediated resistance to sorafenib (Fig. 7A2) or AC220 (Fig. 7B2) was overcome (Fig. 7A3 and B3), and even the anti-leukemia effect of sorafenib (Fig. 7A1) or AC220 (Fig. 7B1) was sensitized regardless of MSCs co-culture, in agreement with the report of FLT3-ITD up-regulating autophagy to mediate resistance to FLT3 inhibitors in AML [13]. Here, FLT3 is linked to leukemia.