RET and medullary thyroid gland carcinoma: The proto-oncogene “Rearranged during Transfection” (RET) is also an important research target because its mutations are the cause of several pathologies including Hirschsprung’s disease and four different endocrine cancers (including multiple endocrine neoplasia 2A and medullary thyroid carcinoma), all due to a multitude of mutations occurring in the RET gene [6, 7, 8, 9].