LEP and head and neck squamous cell carcinoma: The combination of the results for adiponectin and leptin levels show an inverse relationship between leptin and adiponectin whereby systemic leptin levels are increased in patients with premalignant oral lesions and in 1,25(OH)2D3-treated HNSCC patients while adiponectin levels are decreased in these same patient populations and, inversely, adiponectin levels are increased and leptin levels decreased in in untreated HNSCC patients.