Surprisingly, anti-PD-1 therapy achieved significantly better outcomes in HBV+ non-liver cancer patients than in HBV– non-liver cancer patients (p-value = 0.0052), with 15 (42.86%) HBV+ non-liver cancer patients showing partial response (PR) while only 7 (14.29%) HBV– patients showing PR (Fig. 1B, Supplementary Tables 1–3). Here, PDCD1 is linked to liver cancer.