“…Over the past few years, the role of cytokines in regulating thyroid function has been the focus of several studies, which have shown, in general, that cytokines such as tumor necrosis factor ␣, IL-1␣, and IFN-␥ have an inhibitory effect on thyroid function (18). Focusing on IFN-␥, it has been shown, for example, that this cytokine inhibits thyrotropininduced transcription of TG (19), TPO (20), NIS (18), and TSH-R (21) genes, the last one mediated by a reduction of the binding of thyroid transcription factor-1 to the TSH-R promoter (22). All these studies have been performed in vitro, using either primary thyroid cell cultures or, more commonly, the rat thyroid cell line FRTL-5 and, thus, have looked at only the acute effects that the addition of IFN-␥ to the culture medium has on the thyroid cell.…”