PDCD1 and hepatocellular carcinoma: As for the combination of SBRT with ICIs, there are two ongoing clinical trials, including the phase II study (NCT03316872) that assesses the effect of the pembrolizumab combined with SBRT in subjects with advanced HCC who have experienced disease progression after treatment with sorafenib and the phase II/III study (NCT04167293) to test the efficacy of SBRT followed by anti-PD1 antibody for HCC (Table 5).