Antagonizes the function of BMP4 by binding to it and preventing its interaction with receptors. Alters the fate commitment of neural stem cells from gliogenesis to neurogenesis. Contributes to neuronal differentiation of neural stem cells in the brain by preventing the adoption of a glial fate. May play a crucial role in dorsoventral axis formation. May play a role in embryonic bone formation (By similarity). May also play an important role in regulating retinal angiogenesis through modulation of BMP4 actions in endothelial cells. Plays a role during anterior segment eye development. Expressed in the developing cornea and in the eye anterior segment in addition to the retina. Differentially expressed in the fetal brain. There is high expression in cerebellum and neocortex. Expressed in retinal pericytes. By hypoxia in retinal pericytes. The disease is caused by variants affecting the gene represented in this entry. It is uncertain whether Met-1 or Met-7 is the initiator.