RET and medullary thyroid gland carcinoma: With the exception of 6 RET variants in 8 carriers that exhibited no evidence of MTC/PHEO, 55 different RET variants (38 pathogenic and 17 variants) in 276 patients with confirmed or suspected MEN2 are shown in Fig. 1 and Fig. 3, and distribution of pathogenic variants frequencies is summarized in Table 4.