We All Know We Need Them, We Hope They Are Coming, But When?

A number of mechanisms modify thyroid hormone (TH) signaling at the cellular level. To restore TH signaling in patients with hypothyroidism or in patients with the syndrome of TH resistance, it is necessary to quantify the action of THs in a tissue-specific manner. The development of biomarkers that are tissue-specific and respond to TH is a significant first step toward understanding and possibly modifying TH signaling in health and disease states.