KMT2A and leukemia: We analyzed the frequency of hCD45+ leukemic cells with flow cytometry, and found that dexamethasone and RK-20449 as single compounds were not able to eradicate human MLL-rearranged leukaemia cells from PB whereas combination of the two compounds led to significant reduction of hCD45+ cells in the PB of MLL-ALL-engrafted mice (Fig. 3a and Table S2) and prolonged survival of treated mice (Fig. 3b).