TLR7 and head and neck squamous cell carcinoma: Fumi et al. confirmed that intratumoral administration of 1V270 (TLR7 agonist) or SD-101(TLR9 agonist) and blocking PD-1 can suppress the development of primary tumors and prevent tumor metastasis in the head and neck squamous cell carcinoma (HNSCC) model.