CXCL8 and head and neck squamous cell carcinoma: To study the effect of IL-8 on HNSCC progression, the effect of IL-8 (0, 1, 10, 100 and 1000 ng/ml) on the proliferation of variously differentiated HNSCC cells (SCC4, SCC9 and SCC25 cells) and human dysplastic oral mucosa DOK cells was firstly determined.