BRAF and cancer: On the other hand, BRAF mutation analysis is 100% predictive of papillary thyroid carcinoma (high PPV), but most cancers are BRAF-negative (very low NPV); mutations of RAS-family genes mutations are also observed in follicular adenomas and the prevalence of PAX8/PPARγ rearrangements is generally limited in IC nodules with no cases reported in some studies.