BRAF and thyroid cancer: The V600E BRAF mutation uniquely occurs in 45% of PTC, 25% of ATC and does not occur in FTC or other types of thyroid tumors and is highly prevalent in adult PTC, but is infrequent in childhood thyroid cancer as well as in radiation-induced thyroid tumors and is more commonly seen in recurrent PTC (prevalence of 80%–85%) versus primary PTC (prevalence of 45%) [10-12].