Hepatoma-derived growth factor, related protein 3, also known as HDGFRP3, is the original member of a family of polypeptides designated HDGF related proteins (HRPs). This protein enhances DNA synthesis and may play a role in cell proliferation. HDGFRP3 is expressed predominantly in the testis and brain, to an intermediate extent in the heart, and to a slight extent in the ovaries, kidneys, spleen, and liver in humans.