TLR8 and head and neck squamous cell carcinoma: Apart from these combination therapies with TLR8, agonist motolimod with the EXTREME regimen (platinum-carboplatin or cisplatin/fluorouracil/cetuximab) [127], costimulatory agonists, such as OX40, CD40L, CD137, STING, IDO1, and STAT3 inhibitors with ICI therapy [128], adjuvant dendritic cell vaccine against p53, TriAd vaccine targeting brachyury, mucin-1 and carcinoembryonic proteins comprising of adenoviral vaccines are in various stages of clinical trials in the treatment of HNSCC [124,129].