HDAC2 and acute lymphoblastic leukemia: Nineteen driver genes for ALL were mutated at both diagnosis and relapse (Supplementary Fig. S2), including genes encoding the epigenetic regulator proteins HDAC2 and KDM6A, members of important signaling pathways, like NRAS, KRAS, PTPN11, NOTCH1 and FBXW7, and genes encoding the B-cell developmental factors ETV6 and IKZF1.