In addition, the study conducted by Shao et al. 33 detected the on-treatment change in AFP levels in blood of 43 HCC patients treated with PD-1 ICI combined with or without CTLA-4 ICI and identified that high AFP decrease (> 20%) predicted higher ORR (73% vs. 14%, P value < 0.001) and DCR (80% vs. 46%, P value = 0.033) and longer median OS (28.0 vs. 11.2 months, P value = 0.048) and PFS (15.2 vs. 2.7 months, P value = 0.002) than low AFP decrease (≤ 20%). The gene discussed is CTLA4; the disease is hepatocellular carcinoma.