CDH1 and head and neck squamous cell carcinoma: Although the expression of E-cadherin was higher in UPCI-SCC-090 and 93-VU-147T cells than in the other HPV-negative HNSCC cells in steady-state growth (Fig. 1B), suggesting that HPV oncoproteins may influence E-cadherin expression, Fig. 6B showed that the upregulation of E-cadherin expression was more obvious in HPV-negative HNSCC cells than in HPV-positive HNSCC cells after VP treatment, suggesting that VP may be a novel drug inhibiting the invasion and metastasis of HPV-negative HNSCC.