multiple endocrine neoplasia type 4 (Monarch Disease Ontology id MONDO_0012552) (MEN4) is a very rare form of MEN, an inherited cancer syndrome, characterized by parathyroid and anterior pituitary tumors, possibly associated with adrenal, renal, and reproductive organ tumors. Also known as: CDKN1B multiple endocrine neoplasia, MEN4, multiple endocrine neoplasia caused by mutation in CDKN1B, multiple endocrine neoplasia, type IV.