Furthermore, in silico analysis of cohorts included in The Cancer Genome Atlas (TCGA) in a previous study by our group showed that the transcripts of PD-L1 were significantly correlated to that of IRF1 levels in various cancers, including HNSCC [13], suggesting that KPNB1 regulates PD-L1 expression on the surface of irradiated cells via IRF1 regulation. This evidence concerns the gene CD274 and head and neck squamous cell carcinoma.