In addition, a retrospective cohort study looking at HBV reactivation in patients with HBsAg-positive cancer being treated with anti-PD-1/PD-L1 antibody therapies showed that none of the antiviral prophylaxis therapies were the sole substantial risk factor for HBV reactivation (OR 17.50 [95% CI, 1.95–157.07]; p  = 0.004). Here, PDCD1 is linked to cancer.