MECOM and acute myeloid leukemia: To set conditions for validating our results, we confirmed the expression of EVI1 and ΔEVI1 protein isoforms22 in the 3q26 EVI1High AML cell lines (Fig. 2A, B) and demonstrated the dependency of these cells on EVI1 expression (Fig. 2C–E, Supplementary Fig. 3A–C).