EHMT2 and neoplasm: In agreement with a key role of H3K9 methylation in DDR, the G9A inhibitors UNC0638 and A-366 hypersintetized tumor cells to low doses of DSB-inducing agents (Agarwal and Jackson, 2016); moreover, Price and coworkers showed that the G9A specific inhibitor BIX-01294 can significantly increase tumor cell sensitivity to ionizing radiation (Gursoy-Yuzugullu et al., 2017).