PDCD1 and liver cancer: Using targeted cytotoxic T Immune checkpoint inhibition of lymphocyte-associated protein-4 (CTLA-4) and anti-programmed cell death protein-1 (PD-1) cancer immunotherapy with pharmaceutical preparations (ICIs) (24), changing the traditional sorafenib treatment mechanism, and as an adjuvant therapy to a certain extent, the recurrence rate has been reduced (25), expanding the treatment ideas for liver cancer and improving the survival rate (26).