The frequent gene mutations in ATC include TP53 (54.4%), RAS (43%), BRAF (13.8%), PI3K-AKT pathway mutation (17%).[4,8] The most common gene mutations in cases of ATC coexisting with thyroid papillary carcinoma are BRAFV600E (90%) and TERT promoter mutations (95%).[9] In the current case, both ATC and PTC components had BRAFV600E mutation, further indicating that the ATC component was the dedifferentiated component of the papillary carcinoma. The gene discussed is BRAF; the disease is papillary carcinoma.