To determine whether the activation of EGFR was responsible for the upregulation of PD-L1 in HCC, we treated Huh-7, HepG 2, SNU-368 and SNU-739 cells with 100 ng/ml EGF and then measured the mRNA and protein expression of PD-L1. The gene discussed is EGF; the disease is hepatocellular carcinoma.