NKX2-1, also known as thyroid transcription factor 1 (TTF-1), is a protein that functions as a transcription factor, meaning it regulates the expression of genes by binding to specific DNA sequences. It is a member of the NKX family of homeodomain-containing transcription factors and plays a critical role in the development and function of several organs, particularly the thyroid, lung, and brain. One of the primary functions of NKX2-1 is its role in the development of the thyroid gland. NKX2-1 is expressed in the thyroid primordium during embryonic development and is essential for the specification and differentiation of thyroid follicular cells....