DEN is a hepatotoxin and carcinogen that activates liver UPR signalling and increases ATF4 expression during HCC development.53 To examine the effect of ATF4 ablation on chemical liver injury and carcinogenesis, we challenged 3-mo Atf4F/F and Atf4Δhep mice with high-dose DEN (100 mg/kg). This evidence concerns the gene ATF4 and hepatocellular carcinoma.