RET and thyroid tumor: The most frequent rearrangements, RET/PTC (RET gene rearrangements in papillary thyroid carcinomas) (given by the fusion with the CCDC6 gene, formerly H4) and RET/PTC3 (given by the fusion with the NCOA4 gene, formerly ELE1) [19] induce thyroid tumors characterized by nuclear grooves and ground glass cells, continuous slow growth rate, and loss of iodide uptake, in transgenic mice similarly to human PTC [20].