Among those 24 patients with positive histopathology, 6 had already been diagnosed with MTC before RET screening, as they underwent evaluations for asymptomatic thyroid nodules because they knew about index cases in their families (2 relatives of index patient #4, 1 relative of index patient #12) or because they noticed thyroid nodule growth but were not aware that they had a family member with MTC until a broad pedigree was performed (3 relatives of index patient #20, Table 2). This evidence concerns the gene RET and thyroid nodule.