EZH2 and cancer: While mechanisms of derepression of repeat elements in cancer remain to be explored in detail, a role for H3K9me3 malfunction and defective control by key epigenetic regulators, such as the histone methyl transferase SETDB1 [59], DNA methylation [53,54,60], and members of the PRMT family of arginine methyltransferase, are formally implicated in a number of settings [31] as is TP53 [61,62], BRCA1 [16], Rb/EZH2 [17] and PLZF [18], as mentioned earlier.