 Gremlin1, previously known as Drm, is a highly conserved 20.7-kDa, 184 amino acid glycoprotein part of the DAN family and is a cysteine knot-secreted protein.Gremlin1 was first identified in differential screening as a transcriptional down-regulated gene in v-mos-transformed rat embryonic fibroblasts.Gremlin1 (Grem1) is known for its antagonistic interaction with bone morphogenetic proteins (BMPs) in the TGF beta signaling pathway.