Importantly, spermatid broad H3K4me3 regions differ from previously reported broad H3K4me3 domains in oocytes, ICM cells, CD4+ T cells, and tumor cells, in terms of their breadth and intensity (Fig. 3d; Supplementary information, Fig. S7c–e).38–41 Moreover, we demonstrate that SETD1B/KMT2G, an understudied KMT2, is the primary methyltransferase that establishes these broad H3K4me3 domains in spermatids. This evidence concerns the gene CD4 and neoplasm.