It has been identified that in papillary thyroid carcinoma several molecular changes exist: rearranged during transfection (RET)/papillary thyroid carcinoma gene rearrangements, BRAF (B-RAF protooncogene, serine/threonine kinase) gene mutations, RAS (rat sarcoma) mutations, and vascular endothelial growth factor receptor 2 angiogenesis pathways activation. The gene discussed is KDR; the disease is differentiated thyroid carcinoma.