['The differentiation program for human thyroid follicular cells (TFCs) relies on the interplay between sequence-specific transcription factors and transcriptional co-regulators. TAZ (transcriptional co-activator with PDZ-binding motif) is a co-activator that regulates several transcription factors, including PAX8 and NKX2-1, which play a central role in thyroid-specific gene transcription. TAZ and PAX8/NKX2-1 are co-expressed in the nuclei of thyroid cells and TAZ interacts directly with both PAX8 and NKX2-1 leading to their enhanced transcriptional activity on the thyroglobulin (TG) promoter and additional genes.', 'We have studied the use of a small molecule, ethacridine, recently identified as a TAZ activator, in the differentiation of thyroid cells from human embryonic stem (hES) cells. We first derived endodermal cells from hES cells using Activin A followed by induction of differentiation into thyroid cells directed by ethacridine and thyrotropin (TSH).', 'The expression of TAZ was increased in the Activin A derived endodermal cells by ethacridine in a dose-dependent manner and followed by increases in PAX8 and NKX2-1 when assessed by both qPCR and immunostaining. Following further differentiation with the combination of ethacridine and TSH, the thyroid specific genes - TG, TPO, TSHR and NIS were all induced in the differentiated hES cells. When these cells were cultured with extracellular matrix coated dishes we observed thyroid follicle formation and abundant TG protein expression. Furthermore, such hES cell derived thyroid follicles showed a marked TSH induced and dose-dependent increase in radioiodine uptake and protein-bound iodine accumulation.'] Does tAZ induction direct differentiation of thyroid follicular cells from human embryonic stem cells?