The results showed expression of TRL4 in HPV (−) (WSU-HNSCC 6 and 13) and HPV (+) (UPCI-SCC154 and UM-SCC104) OSCC cell lines (Supplementary Figure S3), and the activation of TLR4 displayed different responses among cell lines based on the HPV status (Figure 5C–G). Here, TLR4 is linked to head and neck squamous cell carcinoma.