To date, the majority of published data analysis about HBVr in cancer patients with PD-1 inhibition has been performed based on the absence of antiviral therapy, and indicated that prophylactic antiviral therapy is the key to preventing HBVr (Lee, et al. 2020; Yoo et al. 2022; Zhang, et al. 2019; Papatheodoridis et al. 2022). The gene discussed is PDCD1; the disease is cancer.