The AKAP9 gene encodes the A-Kinase Anchoring Protein 9 (AKAP9), a member of the A-kinase anchor proteins, that regulates cellular localization and function of the protein kinase A. Two missense and one nonsense somatic mutations were identified in 3 cases, two of them showing the biallelic inactivation of the gene, thus suggesting a tumor suppressor activity of AKAP9 in parathyroids. This evidence concerns the gene AKAP9 and neoplasm.