Inactivating mutations of the cell division cycle protein 73 homolog (CDC73) gene that encodes parafibromin, an evolutionarily conserved tumor suppressor protein whose loss of expression has been implicated in parathyroid tumorigenesis, have been reported up to 70% of sporadic PCs, whereas they are rarely detected in benign adenomas [16,17]. This evidence concerns the gene CDC73 and neoplasm.