This invention relates to the field of molecular physiology. Specifically, this invention relates to the treatment of vasculoproliferative conditions, especially those of the eye and in the treatment of tumours that exhibit vascular proliferation. Levels of leucine-rich alpha-2-glycoprotein (Lrg1) have been demonstrated to be increased in patients suffering from such conditions and animal models of such conditions. Antagonists of Lrg1 can be used to treat vasculoproliferative conditions.