IRF1 and squamous cell lung carcinoma: To assess the spectrum and prevalence of genetic defects in the IFNγ-IRF1 signaling pathway in NSCLC, we examined TCGA lung adenocarcinoma (LuAd) and lung squamous cell carcinoma (LuSc) data [25–28] for apparent loss-of-function (LOF) gene alterations (homozygous deletion or truncating mutation) of the IFNγ-IRF1 signaling pathway genes.