Ikzf1 loss-of-function and re-expression experiments in human and mouse T-ALL, coupled with extensive epitranscriptomic analysis of primary T-ALL and thymocytes, identified novel mechanisms that regulate tumor suppression in T-ALL (Fig. 8):Critical role of IKAROS-HDAC1 complexes in regulation of global facultative heterochromatin landscape. The gene discussed is IKZF1; the disease is acute lymphoblastic leukemia.