Thyroid hormone's action on progenitor/stem cell biology: New challenge for a classic hormone?

► The thyroid hormones and the nuclear receptors TR control the developmental and the homeostatic processes in several tissues. ► The intestine and the retina are organ targets of the thyroid hormones and the TRs. ► The action of the thyroid hormones and TRs is coordinated and integrated with other signaling pathways. ► New data also describe their involvement in gut epithelial stem cell physiology.