EZH2 and breast cancer: Other noteworthy enzymes involved in the perpetration of a conducive tumour microenvironment by means of epigenetic regulation in hereditary breast cancer include histone methyltransferases such as the enhancer of zeste homologue 2 (EZH2) that represses target gene expression [9] and lysine methyltransferase 2 (KMT2) that promotes the expression of oestrogen-dependent oncogenes like the epidermal growth factor [111].