In the present study RET/PTC1 and RET/PTC3, the most frequent rearrangements detected in papillary carcinomas, occurred with a similar frequency: RET/PTC1 was present in five cases of PTC (10.9%) and RET/PTC3 in three cases (6.5%). This evidence concerns the gene NCOA4 and thyroid gland papillary carcinoma.