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.
[1][2] Gremlin1 was first identified in differential screening as a transcriptional down-regulated gene in v-mos-transformed rat embryonic fibroblasts.
[3] Gremlin1 (Grem1) is known for its antagonistic interaction with bone morphogenetic proteins (BMPs) in the TGF beta signaling pathway.
As stated above, GREM1 is a member of the cysteine-knot superfamily similar to vascular endothelial growth factor (VEGF).
[13] Grem1 expression is found in many cancers and is thought to play important roles in uterine cervix, lung, ovary, kidney, breast, colon, pancreas, and sarcoma carcinomas.
[1] In addition, overexpression of Grem1 in the mouse limb bud inhibits BMP signaling which can lead to digit loss as well as polydactyly.