CD8A and gastric cancer: Flow cytometry, ELISA, WB, and PCR were used to examine changes in the number of immune cell populations in the spleen, secretion of cytotoxic factors by immune cells, opioid receptors, AKT/mTOR, and immune checkpoint proteins, respectively, in CD8<sup>+</sup>T cells.<h4>Results</h4>We found that changes in perioperative immune function strongly correlated with TLR4 expression on the surface of immune cells in patients with gastric cancer.