In BRCA1-mutated BC, EHMT1 (KMT1D) is up-regulated, leading to H3K9 methylation and decrease in GCN5-mediated H3K9ac, which synergistically promote the inhibition of phosphatidylethanolamine N-methyltransferase to potentiate BC tumorigenesis (Li D. et al., 2014). Here, EHMT1 is linked to breast cancer.