Samuel Murray has hypothesized that the first-discovered member of this class of molecules was actually a fragment of spp-24 that binds to them. Mesenchymal cells of the septum transversum use one of these molecules as a signal to induce albumin expression in the endoderm of the liver. Interaction between type I and type II receptors of this class of molecules can lead to the initiation of transcription of R-Smads, and juvenile polyposis can be mimicked through overexpression of noggin, an inhibitor of them. They were first discovered by Marshall Urist, and a gradient 
Samuel Murray has hypothesized that the first-discovered member of this class of molecules was actually a fragment of spp-24 that binds to them. Mesenchymal cells of the septum transversum use one of these molecules as a signal to induce albumin expression in the endoderm of the liver. Interaction between type I and type II receptors of this class of molecules can lead to the initiation of transcription of R-Smads, and juvenile polyposis can be mimicked through overexpression of noggin, an inhibitor of them. They were first discovered by Marshall Urist, and a gradient in them regulates the expression of Msx, a protein necessary for the specification of the neural crest. For 10 points, name this class of proteins named for their ability to induce formation of new bone tissue.
Samuel Murray has hypothesized that the first-discovered member of this class of molecules was actually a fragment of spp-24 that binds to them.
BMPs [or bone morphogenetic proteins; or osteogenic proteins; or OPs]