In this study, we examined the infiltrating level of TIL, CD4+TIL, and CD8+TIL in naïve and post‐chemotherapy NCT‐NSCLC tumor tissue specimens, and explored their prognostic value in patients with NCT‐NSCLC, both naïve and post‐chemotherapy tumor tissue specimens came from the same patients. The gene discussed is CD8A; the disease is non-small cell lung carcinoma.