RET and medullary thyroid gland carcinoma: RET is a proto‐oncogene that encodes a receptor tyrosine kinase expressed in neural crest derived cells.8 In hereditary MTC cases germline point mutations in RET are identified in 95%‐98% cases5, 9, 10, 11 whereas 40%‐60% sporadic MTC cases have somatic RET mutations.8, 12, 13 Other than the high penetrance gain‐of‐function germline or somatic RET mutations, no other genetic, lifestyle or environmental risk associations have been clearly established for MTC.