Contacts:

Barbara Sullivan Sullivan& Associates (714) 374-6174 bsullivan@sullivanpr.com

Christina Andrian diaDexus, Inc. (650) 246-6476 candrian@diadexus.com

DIADEXUS TO PRESENT AT BIO INVESTORFORUM 2006

South San Francisco, CA - October 16, 2006 - Patrick Plewman, president and chief executive officer of diaDexus, will provide a corporate overview and highlight the commercial opportunity for the PLAC® test at the BIO InvestorForum 2006 at the Palace Hotel in San Francisco, Wednesday, Oct. 18, 2006. The presentation is scheduled for 11:40 a.m. PDT.

BIO InvestorForum 2006 is hosted by the Biotechnology Industry Organization and will be attended by public and private biotechnology investors. The program showcases leading growth companies in life sciences.

About diaDexus
diaDexus, Inc., a privately held biotechnology company based in South San Francisco, is focused on the discovery, development, and commercialization of novel, patent-protected diagnostic products with high clinical value. The company's lead product, the PLAC test, is a simple blood test that measures the concentration of a novel risk factor for coronary heart disease and stroke-lipoprotein-associated phospholipase A2 (Lp-PLA2)-a cardiovascular-specific inflammatory marker implicated in the formation of vulnerable, rupture-prone plaque. The PLAC test is cleared for marketing by the U.S. Food and Drug Administration as an aid in determining risk for coronary heart disease and ischemic stroke associated with atherosclerosis. In addition to the PLAC test, diaDexus is developing a pipeline of novel cancer diagnostic tests.

For more information, visit www.plactest.com or www.diaDexus.com