MEF2C and leukemia: Notably, 96.2% of leukemias (n = 51/53) harbored alterations in genes that regulate normal lymphoid differentiation (IKZF1, PAX5, BTG1, RUNX1, EBF1, MEF2C, TSC22D1, FOXP1, LEF1, ETV6, TCF3 and TCF4; mean of 2.1 alterations per leukemia; Extended Data Fig. 5a,b) and consistent with previous findings4.