EHMT2 and breast cancer: Di- and trimethylation of H3K9 provides a binding site for chromodomain-containing proteins of the heterochromatin protein 1 family; this binding leads to gene repression via changes in heterochromatin structure [14, 15], and this epigenetic regulation by G9a decreases E-cadherin expression and, subsequently, increases cell migration in breast cancer cell lines [16].