This study examined whether BRAFV600E is associated with CLT and PTC. BRAFV600E is only observed in anaplastic carcinoma originated from PTC or papillary carcinoma and not in other thyroid cancers, including follicular carcinoma. BRAF is a B-type Raf kinase located on chromosome 7 and is the most potent activator of the mitogen-activated protein kinase/extracellular-signal-regulated kinase (MEK-ERK) pathway. Here, BRAF is linked to undifferentiated carcinoma.