These analyses revealed that high levels of CD8+ T lymphocytes were associated with improved overall survival in studies with large numbers of patients (≥200; HR = 0.73; 95% CI, 0.63–0.83), histology subtype (HR = 0.68; 95% CI, 0.54–0.86 for squamous cell carcinoma; and HR = 0.92; 95% CI, 0.85–0.99 for NSCLCs), European patients (HR = 0.76; 95% CI, 0.65–0.88). The gene discussed is CD8A; the disease is squamous cell carcinoma.