Although the detection of molecular alterations in HT, such as the presence of the papillary carcinoma-related fusion gene RET/PTC, is still a matter of discussion, the loss of genetic material at specific chromosomal loci has been demonstrated by Hunt and co-workers (Wirtschafter et al, 1997; Hunt et al, 2002; Nikiforova et al, 2002). This evidence concerns the gene RET and papillary carcinoma.