PDCD1 and hepatocellular carcinoma: For another combination (ipilimumab plus nivolumab, monoclonal antibodies against CTLA-4 immune checkpoints and PD-1 immune checkpoints, respectively), there was a Checkmate 040 randomized clinical study (57), a multicenter, open-label, multicohort, phase I/II trial, designed to test the efficacy and safety of varying dosages of combination therapy for advanced HCC patients who previously received sorafenib.