Although the Trp589Arg missense Galnt3 mutation associated with TCAL in the mouse has not been identified in patients with FTC, it is important to note that Trp589 is conserved in both species and that the Trp589Arg mutation is representative of 40% of GALNT3 abnormalities which are also missense mutations in patients with FTC and HHS [3], [14]–[19]. This evidence concerns the gene GALNT3 and thyroid cancer, nonmedullary, 2.