Nidogens, previously referred to as entactins, are sulfated monomeric glycoproteins found in the basal lamina. Two forms exist in mammals: nidogen-1 (NID1) and nidogen-2 (NID2). Nidogen-1 consists of three globular domains (G1–G3) connected by two linker segments and serves as a key organizer of basement membrane structure. It facilitates the formation of ternary complexes with laminins, collagen IV, perlecan, and fibulins. Nidogens have been implicated in the development of the heart and lungs.
