The presence of exon 10 mutations in RET was strongly associated with the development of MTC, with the following age-related penetrance: 3.2% by age 11 years, 6.5% by age 20, 32% by age 30, 47% by age 37, 84% by age 60, 95% by age 70, and 100% by age 83 (Fig 3). Here, RET is linked to medullary thyroid gland carcinoma.