We identified the chromatin state of the Ikaros gene targets in ALL leukemia cells and found that Ikaros suppresses the expression of its targets by recruiting H3K9me3 or H3K27me3 [34], and up-regulates gene expression by increasing the binding of H3K4me3 via KDM5B in the promoter region of its targets [34, 36, 43]. The gene discussed is KDM5B; the disease is leukemia.