In 2012, I came to the United States to pursue postdoctoral research and was privileged to work with Dr. Samuel Refetoff on the role of genetics in thyroid disease. We worked on characterizing the genetic defects in patients with rare thyroid disorders and dissecting the mechanism of action of novel mutations, and identified a novel mechanism of TBG deficiency caused by a mutation in a liver specific enhancer of the promoter of the TBG gene.