The protein encoded by this gene induces proliferation, migration, and fenestration (the formation of membrane discontinuities) in capillary endothelial cells derived from endocrine glands. It has little or no effect on a variety of other endothelial and non-endothelial cell types. Its expression is restricted to the steroidogenic glands (ovary, testis, adrenal, and placenta), is induced by hypoxia, and often complementary to the expression of vascular endothelial growth factor (VEGF), suggesting that these molecules function in a coordinated manner.