In an effort to elucidate the underlying molecular mechanisms of the transition from indolent DTC to virulent ATC, we reported the altered expression of several molecules such as UDP-GalNAc: polypeptide N-acetylgalactosaminyl transferases-3 (GalNAc-T3) and epithelial cell adhesion molecule (EpCAM) together with CD44v6 and claudin-7 as well as aldehyde dehydrogenase 1 (ALDH1) in the development of the aggressive phenotype of thyroid cancer [6, 8]. The gene discussed is EPCAM; the disease is thyroid cancer.