ATF4 and hepatocellular carcinoma: Here we explored the role of the ER stress mediator activating transcription factor 4 (ATF4) in DEN- and high-fat diet (HFD)-induced HCC in major urinary protein (MUP)–urokinase-type plasminogen activator (uPA) mice, which express the secreted protein uPA from the MUP promoter.