STAT3 and cancer: Since the role of cytokines, particularly IL6, has been well elucidated in terms of STAT3-mediated oncogenesis in various human cancer types, including thyroid cancer, and since it is considered to be a plausible target in the development of cancer therapeutics [30,53,54], we also investigated the role of IL6/STAT3 signaling in PTC cells treated with curcumin and cisplatin.