Gecko polypeptide mixture at 0.3 mg/mL upregulated GRP78 protein expression and induced ROS production in hepatocellular carcinoma HepG2 cells, activated the ERS-mediated PERK signaling pathway and upregulated ATF4 expression to promote DDIT3 and CHOP expression in the cells, ultimately inducing apoptosis through starting of the apoptosis-associated proteins PARP and caspase-3 (Duan et al., 2018). The gene discussed is ATF4; the disease is hepatocellular carcinoma.