Gremlin-1 (isoform-1) belongs to a group of diffusible proteins which bind to ligands of the TGF-β family and regulate their activity by inhibiting their access to signaling receptors. The interplay between TGF-β ligands and their natural antagonists has major biological significance during development processes, in which cellular response can vary considerably depending upon the local concentration of the signaling molecule. Gremlin is highly expressed in the small intestine, fetal brain, and colon and lower expression in brain, prostate, pancreas and skeletal muscle. Gremlin-1 regulates multiple functions in early development by specifically binding to and inhibiting the function of BMP-2, -4, and -7. It also plays a role in car