We collected baseline (before receiving PD-1 inhibitors) peripheral blood samples from advanced GC patients (n=54) who underwent PD-1 inhibitors and platinum drugs from January 2022 to December 2023 and investigated PD-1 expression on effector memory T (TEM) between responders and non-responders according to Response Evaluation Criteria in Solid Tumors (RECIST 1.1) guidelines by low-dose computed tomography scan evaluation. The gene discussed is PDCD1; the disease is gastric cancer.