Furthermore, a restricted co-expression among these three markers was observed in both squamous cell carcinomas (n = 501; Pearson = 0.849, Spearman = 0.819, for CD8 and IFN-γ; Pearson = 0.285, Spearman = 0.403, for CD8 and PD-L1; Pearson = 0.232, Spearman = 0.375, for PD-L1 and IFN-γ) and adenocarcinomas (n = 517; Pearson = 0.737, Spearman = 0.793, for CD8 and IFN-γ; Pearson = 0.344, Spearman = 0.555, for PD-L1 and IFN-γ; Pearson = 0.290, Spearman = 0.537, for CD8 and PD-L1), and remained statistically significant (p < 0.001) (Figure 4C). This evidence concerns the gene CD8A and squamous cell carcinoma.