ATF4 and breast cancer: Recent reports suggest that severe hypoxia induces ER stress via PERK-ATF4 axis and ATF4 binding on the LC3B promoter (+541~+656) mediates autophagy breast cancer cells, whereas G9a directly binds on LC3B promoter and regulates repressively LC3B expression, and G9a inhibition activates LC3B expression and autophagy31,32.