Cytokine that inhibits the activity of BMP2 and BMP4 in a dose-dependent manner, and thereby modulates signaling by BMP family members. Contributes to the regulation of embryonic morphogenesis via BMP family members. Antagonizes BMP4-induced suppression of progesterone production in granulosa cells. Homodimer. Interacts with BMP2, BMP4 and BMP7, but has lower affinity for BMP7 than for BMP2 and BMP4. Binds heparin; this impairs the interaction with BMP2. N-glycosylated. The disease is caused by variants affecting the gene represented in this entry. Belongs to the DAN family.