An oral cancer study displayed that the oxidized mtDNA in cytosol induced IFN signaling through the cGAS/STING pathway and thus elevated PD-L1 and IDO-1 expression, which inhibited T-cell function through inducing IFN and IL-6 production from macrophages (Cheng et al., 2020). This evidence concerns the gene IFNA1 and lip and oral cavity carcinoma.