Licitra et al. found that epidermal growth factor-like (EGF-like) growth factors in WF derived from surgically resected head and neck squamous cell carcinomas (HNSCCs) induced proliferation of squamous carcinoma cell lines by promoting epidermal growth factor receptor (EGFR) expression and activating EGFR pathway [10]. Here, EGFR is linked to squamous cell carcinoma.