PDCD1 and gastric cancer: This disruption can lead to uncontrolled T-cell activation and autoimmune responses, causing inflammation and damage to various organs.Nivolumab, a human IgG4 monoclonal antibody that acts against PD-1 and blocks a co-inhibitory signal on PD-1/PD-L1 and PD-1/PD-L2 axis, is emerging as a novel treatment strategy for advanced gastric cancers [4,5].