Inhibitor of bone morphogenetic proteins (BMP) signaling. Homodimer; disulfide-linked. First appears at the end of gastrulation in the axial mesoderm. By the 5-somite stage, expressed in telencephalon and anterior diencephalon. From early segmentation stages until the end of tail elongation, found in the tail bud. Expression is maintained during somitogenesis. At the 10-somite stage, detected in the antero-medial aspect of the somites. At 20 hours of development expression is observed in the ventro-medial part of the somite as well as in a small population of cells located more dorsally, adjacent to the neural tube. As development proceeds, expression in the dorsal somite is progressively lost, while ventro-medial sclerotomal cells lining the developing axial vasculature continue to show expression until 30 hours of development. In the head, expression is maintained in the telencephalon and anterior diencephalon until late embryogenesis. At the 15-somite stage, expressed in the forebrain, dorsal hindbrain and dorsal caudal spinal cord. Until late stages of embryogenesis strong expression is observed in the dorsal hindbrain walls. Belongs to the noggin family.