STAT-3 is overexpressed in several tumor cells, including cholangiocarcinoma, breast cancer, prostate cancer, head and neck squamous cell carcinoma, lymphomas and leukemia, brain tumors, gastric cancer, esophageal cancer, ovarian cancer, nasopharyngeal cancer, and pancreatic cancer [27]. This evidence concerns the gene STAT3 and head and neck squamous cell carcinoma.