In the present study, we demonstrate that G9a accumulation in hypoxia leads to the transcriptional repression of CDH10. We show that CDH10 expression is directly regulated by G9a under reduced oxygen pressure and that its loss enhances breast cancer cell motility, even in metastatic cell lines that have already lost expression of E-cadherin and EpCAM. The gene discussed is EHMT2; the disease is breast cancer.