PDCD1 and cancer: Indeed, the blockage of PD-1/PD-L1 expression and tumor-infiltrating lymphocytes (TIL) in patients with HCC leads to the discontinuation of immunosuppressive effect by the cancer cells and therefore reactivates cytotoxic T-cells to identify and eradicate the cancer cells (11). Nivolumab was the first second-line treatment for patients with advanced HCC to be approved, and based on the phase I/II Checkmate 040 study (7), the objective response rate (ORR) was 20%, the disease control rate (DCR) was 64%, and PFS was 4.1 months for patients after sorafenib failure.