CD8A and squamous cell lung carcinoma: To rule out possible bias induced by the limited tumor samples and/or the effect of marker heterogeneity, we further analyzed the mRNA levels of PD-L1, CD8, and IFN-γ acquired by RNA-sequencing from 1018 whole tissue section tumor samples from The Cancer Genome Atlas lung cancer datasets (lung squamous cell carcinoma, TCGA provisional, RNA Seq V2, 501 samples; lung adenocarcinoma, TCGA provisional, RNA Seq V2, 517 samples).