For his MTC tumor, despite the lack of previously reported MTC-related alterations, a de novo (acquired in embryo development, causing genetic mosaicism) frameshift mutation c.3338delT in the NF1 gene was detected with a VAF as high as 76.1%, strongly suggestive of a driver event (Supplementary Fig. S3e and Table S3). The gene discussed is NF1; the disease is medullary thyroid gland carcinoma.