These results showed that RFESD had a significant positive association with two of the four key ICB genes, including CD274 (r = 0.136; P = 1.16e− 02) and PDCD1LG2 (r = 0.117; P = 2.97e− 02; Fig. 12F-I), indicating that RFESD is an indispensable regulator in HCC immunotherapy. The gene discussed is PDCD1LG2; the disease is hepatocellular carcinoma.