<prompt> Which of the following is not a feature of Papillary carcinoma of thyroid?Rearrangement of RET geneRearrangement of NTRK1 geneMutation of BRAF geneMutation of RAS gene  <response>: Most papillary carcinomas have gain-of-function mutations or rearrangements involving: RET gene NTRK1 receptor tyrosine kinases Serinethreonine kinase BRAF, which is component of MAPK pathway. RAS mutations are seen in follicular carcinoma of thyroid. 