Advances in Endocrinology http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. The Emerging Roles of Thyroglobulin Thu, 10 Apr 2014 00:00:00 +0000 http://www.hindawi.com/journals/aen/2014/189194/ Thyroglobulin (Tg), the most important and abundant protein in thyroid follicles, is well known for its essential role in thyroid hormone synthesis. In addition to its conventional role as the precursor of thyroid hormones, we have uncovered a novel function of Tg as an endogenous regulator of follicular function over the past decade. The newly discovered negative feedback effect of Tg on follicular function observed in the rat and human thyroid provides an alternative explanation for the observation of follicle heterogeneity. Given the essential role of the regulatory effects of Tg, we consider that dysregulation of normal Tg function is associated with multiple human thyroid diseases including autoimmune thyroid disease and thyroid cancer. Additionally, extrathyroid Tg may serve a regulatory function in other organs. Further exploration of Tg action, especially at the molecular level, is needed to obtain a better understanding of both the physiological and pathological roles of Tg. Yuqian Luo, Yuko Ishido, Naoki Hiroi, Norihisa Ishii, and Koichi Suzuki Copyright © 2014 Yuqian Luo et al. All rights reserved.