Interestingly, the 11q13 locus also contains the Multiple Endocrine Neoplasia type 1 gene (MEN1; MIM♯ 131100), 2.4 megabases upstream from the AIP gene, which can cause familial pituitary adenomas; however, the phenotype of MEN1 and FIPA is different. This evidence concerns the gene AIP and pituitary gland adenoma.