EGF and head and neck squamous cell carcinoma: In our previous search to find endogenous tumour suppressors functioning to prevent head and neck squamous cell carcinoma (HNSCC), we cultured HNSCC cells under serum-free conditions and treated them with epidermal growth factor, whose receptor is frequently hyperactive in HNSCC and cancers of other tissues, and focused on molecules down regulated in this type of cancer.