- PD-L1 is overexpressed in oral cancer patient samples↓ PD-L1 expression in oral cancer patient samples↓ IFN-γ secretion of oral cancer cells↓ IFN-γ-induced JAK2/STAT1 activityLeading to: Inhibition of IFN-γ-induced PD-L1 expression in oral cancer cells. This evidence concerns the gene JAK2 and lip and oral cavity carcinoma.