However, studies have confirmed that the HGF/c-Met signaling pathway is abnormally activated in various types of cancer, such as lung cancer, breast cancer, gastric cancer, and head and neck squamous cell carcinoma (HNSCC), and is involved in the oncogenesis, invasion, and angiogenesis of tumors (10, 11). This evidence concerns the gene HGF and head and neck squamous cell carcinoma.