PDCD1 and gastric cancer: In 2022, the National Comprehensive Cancer Network (NCCN) clinical practice guidelines for gastric cancer included the use of anti-PD-1 (Nivolumab) agents in combination with fluoropyrimidine and platinum-based drugs as one of the first-line treatment options for systemic treatment of metastatic or locally advanced gastric cancer (in the absence of local treatment indications) [20].