NF1 and medullary thyroid gland carcinoma: The p.Leu790Phe variant is classified at the lowest risk level and is generally associated exclusively with MTC [53]; it is therefore possible that, in this individual, the risk of developing a PCC was greater than that of the ordinary carriers of this variant, due to the co-presence of the mutation of NF1, another gene whose alterations are associated with an increased risk of developing PCC.