The total number of lymphocytes was found to significantly decrease after radical gastrectomy, which can last for more than 1 week, and immune checkpoint molecules, such as programmed cell death ligand 1 (PD-L1) and lymphocyte activation gene-3 (LAG-3), were upregulated on CD4+ and CD8+ T cells after surgery for GC [78]. This evidence concerns the gene CD4 and gastric cancer.