The GTPase of the immunity-associated protein (GIMAP) family of proteins include seven members that are expressed by genes residing on human chromosome 7. GIMAP proteins have been implicated in the regulation of lymphomyeloid cell survival. GIMAP1 (GTPase, IMAP family member 1), also known as IMAP1 (immunity-associated protein 1), HIMAP1 or IMAP38, is a 306 amino acid single-pass type IV membrane protein of the endoplasmic reticulum (ER) belonging to the GIMAP family. Encoded by a gene located on human chromosome 7, GIMAP1 is expressed primarily in spleen with lower levels found in lymph node. Chromosome 7 houses over 1,000 genes, comprises nearly 5% of the human genome and has been linked to Osteogenesis imperfecta, Pendred syndrome, Lissencephaly, Citrullinemia and Shwachman-Diamond syndrome.