RET and medullary thyroid gland carcinoma: Genotype-phenotype analysis indicated that patients with the C618/C620 mutation had a significantly higher positive rate of cervical N1 than those with the C609/C611 mutation (P = 0.011), suggesting that both TNM staging and RET mutation genotypes should be considered in the clinical diagnosis and treatment of MEN2A-MTC for comprehensive evaluation and analysis [1,2,4,13].