Gremlin is also known as Cysteine knot superfamily 1, BMP antagonist 1 (CKTSF1B1), DAN domain family member 2 (DAND2), Down-regulated in Mos-transformed cells protein (DRM), Increased in high glucose protein 2 (IHG-2), Cell proliferation-inducing gene 2 protein (PIG2) or Gremlin-1 (GREM1), which is highly expressed in small intestine, fetal brain and colon. Gremlin / GREM-1 interacts with SLIT1 and SLIT2 in a glycosylation-dependent manner. Gremlin may play an important role during carcinogenesis and metanephric kidney organogenesis, as a BMP antagonist required for early limb outgrowth and patterning in maintaining the FGF4-SHH feedback loop. Gremlin down-regulates the BMP4 signaling in a dose-dependent manner and acts as inhibitor of monocyte chemotaxis.