The present study shows for the first time that follicular adenomas present specific nuclear HLTF immunostaining (using the ART2 rabbit anti-serum recognizing the HLTF wild type protein as well as the two HLTF variants, HLTFMet1ΔA and HLTFMet1ΔB), whereas papillary carcinomas exhibit cytoplasmic expression. This evidence concerns the gene ART1 and papillary carcinoma.