<prompt> Gene involved in medullary carcinoma thyroid isRet Proto OncogeneFap geneRb geneBRCA 1 gene  <response>: The RET proto-oncogene encodes a receptor tyrosine kinase for members of the glial cell line-derived neurotrophic factor GDNF family of extracellular signalling molecules.RET loss of function mutations are associated with the development of Hirschsprungs disease, while gain of function mutations are associated with the development of various types of human cancer, including medullary thyroid carcinoma, multiple endocrine neoplasiastype 2A and 2B, pheochromocytoma and parathyroid hyperplasia 