Deciphering direct and indirect influence of thyroid hormone with mouse genetics.

T3, the active form of thyroid hormone, binds nuclear receptors that regulate the transcription of a large number of genes in many cell types. Unraveling the direct and indirect effect of this hormonal stimulation, and establishing links between these molecular events and the developmental and physiological functions of the hormone, is a major challenge. New mouse genetics tools, notably those based on Cre/loxP technology, are suitable to perform a multiscale analysis of T3 signaling and achieve this task.