In 471 Hashimoto's thyroiditis (HT) patients, the significant difference was revealed in anti-thyroid peroxidase antibody (TPOAb) concentration, the cytokeratin-19 (CK-19) expression, the occurrence of the B-Raf proto-oncogene serine/threonine kinase (BRAF) mutations and the rearrangement in transformation (RET)/PTC.