ATF4 and viral infectious disease: ATF4 is a key downstream effector of the ER and integrated stress responses, which are triggered by nutrient deprivation, viral infection, and oxidative stress.67 However, under persistent stress or when adaptation is insufficient, ATF4 promotes cell death.68 Of note, liver-specific ATF4 ablation inhibits hepatic steatosis,30,31,33–35 which could be a protective response that prevents further progression to steatohepatitis.