A method of diagnosing tumor in a mammal, said method comprising (a) contacting an anti-PRO197, anti-PRO207, anti-PRO226, anti-PRO232, anti-PRO243, anti -PRO25 6, anti -PRO269, anti-PRO304, anti-PRO339, anti-PRO1558, anti-PRO779, anti-PRO1185, anti-PRO1245, anti-PRO1759, anti-PRO5775, anti-PRO7133, anti-PRO7168, anti-PRO5725, anti-PRO202, anti-PRO206, anti-PRO264,anti-PRO313, anti-PRO342, anti-PRO542, anti-PRO773, anti-PRO861, anti-PRO1216, anti-PRO1686, anti-PRO1800, anti-PRO3562, anti-PRO9850, anti-PRO539, anti-PRO4316 or anti-PRO4980 antibody with a test sample of tissue cells obtained from the mammal, and (b) detecting the formation of a complex between said antibody and a PRO197, PRO207, PRO226, PRO232, PRO243, PRO256, PRO269, PRO274, PRO304, PRO339, PRO1558, PRO779, PRO1185, PRO1245, PRO1759, PRO5775, PRO7133, PRO7168, PRO5725, PRO202, PRO206, PRO264, PRO313, PRO342, PRO542, PRO773, PRO861,PRO1216, PRO1686, PRO1800, PRO3562, PRO9850, PRO539, PRO4316 or PRO4980 polypeptide in the test sample, wherein the formation of a complex is indicative of the presence of a tumor in said mammal.