To verify the antitumour function of PD-1+CD8+ TILs in HNSCC, SCC7, a head and neck squamous cell carcinoma was used.28 The surface expression of MHC-I and PD-L1 of SCC7 cells was elevated in response to IFN-γ (Fig. 5a). Here, IFNG is linked to head and neck squamous cell carcinoma.