SETDB1 and cancer: In addition to the PRC complex, several regulators of histone H3K9 methylation, such as the SET domain-containing histone methyltransferases SETDB1 and G9a (also known as euchromatic histone lysine N-methyltransferase 2, EHMT2), play important roles in regulating pluripotency and cancer stemness [109,110].