Among key epigenetic regulators, Ezh2, a histone methyltransferase and a central component of the Polycomb Repressive Complex 2 (PRC2), has been shown to drive tumour progression through H3K27 trimethylation (H3K27me3)-mediated transcriptional repression of tumour suppressor genes [39–41]. This evidence concerns the gene PRDM9 and neoplasm.