To investigate whether Sharp1 deletion affects the initiation of other subtypes of MLLr-AML, the MLL-AF9 fusion gene15 was retrovirally transduced into LSK cells from Sharp1+/+ or Sharp1−/− mice and subsequently 200,000 cells were transplanted into sublethally irradiated (650 rads) CD45.1+ congenic mice (Supplementary Fig. 4c). Here, BHLHE41 is linked to acute myeloid leukemia.