A method for stimulating endothelial cell growth in a mammal comprising administering to the mammal a PRO21, PRO181, PRO205, PRO214, PRO221, PRO231, PRO238, PRO241, PRO247, PRO256, PRO258, PRO263, PRO265, PRO295, PRO321, PRO322, PRO337, PRO363, PRO365, PRO533, PRO697, PRO725, PRO771, PRO788, PRO791, PRO819, PRO828, PRO836, PRO846, PRO865, PRO1005, PRO1006, PRO1025, PRO1054, PRO1071, PRO1079, PRO1080, PRO1114, PRO1131, PRO1155, PRO1160, PRO1186, PRO1192, PRO1244, PRO1272, PRO1273, PRO1279, PRO1283, PRO1286, PRO1306, PRO1309, PRO1325, PRO1329, PRO1347, PRO1356, PRO1376, PRO1382, PRO1411, PRO1412, PRO1508, PRO1550, PRO1556, PRO1760, PRO1787, PRO1801, PRO1868, PRO1887, PRO3438, PRO3444, PRO4324, PRO4333, PRO4341, PRO4342, PRO4353, PRO4354, PRO4356, PRO4371, PRO4408, PRO4422, PRO4425, PRO4499, PRO5723, PRO5737, PRO6029, PRO6071, PRO9821, PRO9873, PRO10008, PRO10096, PRO19670, PRO20040, PRO20044, PRO21055 or PRO21384 polypeptide, or agonist thereof, wherein endothelial cell growth in said mammal is stimulated.