A particularly strong correlation was found in squamous cell lung cancer between FAP and CD8 + T cell density, which was stronger than in the non-squamous cell lung cancer group (Spearman’s rho  – 0.34, p = 0.01; Spearman’s rho  – 0.30, p = 0.008, respectively). This evidence concerns the gene CD8A and squamous cell lung carcinoma.