Schneider et al. reported that miR-155 expression was positively correlated with Meis1 expression level in MLL-rearranged AML and first indicated that the transforming efficacy of MLL-fusions remained unaltered in the absence of miR-155, while knocking out miR-155 did not affect in vitro leukemia formation or progression [32]. Here, KMT2A is linked to acute myeloid leukemia.