<prompt> Follicular carcinoma of thyroid is mostly due to mutation ofHRASKRASNRASNTRK1  <response>: Mutations in HRAS, KRAS, or more commonly NRAS occur in 25 of FTCs, 15 of PTCs almost always the follicular variant of PTC, and 5 of follicular adenomas. Follicular thyroid is also associated with PAX8-PPARg. PAX8-PPARg appears to be confined to atypical follicular adenomas and FTC, and has not been detected in PTC or either poorly differentiated or undifferentiated anaplastic thyroid carcinomas RET and NTRK1 or more common in papillary thyroid cancer. Source : Devita principles of oncology 10th edition Pg: 1172 