Contacts:

Patrick Plewman diaDexus, Inc. (650) 246-6400

Carolyn Bumgardner Wang WeissComm Partners (415) 362-5018 x123 carolyn@weisscommpartners.com

DIADEXUS ANNOUNCES PRESENTATIONS HIGHLIGHTING THE ROLE OF Lp-PLA2 IN CARDIOVASCULAR DISEASE AT THE AMERICAN COLLEGE OF CARDIOLOGY SCIENTIFIC SESSIONS 2005

South San Francisco, CA- March 4, 2005 - diaDexus announced today multiple presentations highlighting the role of Lipoprotein-Associated Phospholipase A2 (Lp-PLA2), in vascular disease. The presentations will take PLA2e at the American College of Cardiology (ACC) Scientific Sessions being held March 6-9, 2005 at the Orange County Convention Center in Orlando, FL.

The presentations are as follows:

Sunday, March 6, 2005
Session Title: Lipoprotein-Associated Phospholipase A2 Plasma Concentrations Predict Cardiovascular Events in Patients with Coronary Heart Disease
Research institution: University of Ulm, Ulm, Germany
Poster Pres #1013-101: 11:00 a.m. - 12:00 p.m.

Monday, March 7, 2005
Session Title: Lipoprotein-Associated Phospholipase A2 Independently Predicts the Angiographic Diagnosis of Coronary Artery Disease
Research institution: LDS Hospital, Intermountain Health Care, Salt Lake City, Utah
Oral Pres #814-7: 3:00 p.m. - 3:15 p.m.

Tuesday, March 8, 2005
Session Title: Lipoprotein-Associated Phospholipase A2 (Lp-PLA2) is Significantly Associated with Carotid Intimal Medial Thickness in Asian Indian Population: Arizona Heart Institute Multiple Emerging Risk Factor Assessment of Atherosclerosis among Asian Indians (AHIMSA) Study Research institution: Arizona Heart Institute, Phoenix, AZ
Poster Pres #1129-105: 9:00 a.m. - 10:00 a.m.

About Lp-PLA2
Lp-PLA2 is an enzyme, primarily bound to LDL cholesterol, and has been found to be present in atherosclerotic plaque. Multiple published studies in peer-reviewed journals show a statistically significant relationship between elevated Lp-PLA2 and the risk of a major cardiovascular event.

About diaDexus
diaDexus, Inc., a privately held biotechnology company, based in South San Francisco, California, is focused on the discovery, development and commercialization of novel, patent-protected diagnostic and therapeutic products with high clinical value. The PLA2T test, developed by diaDexus, is a blood test cleared by the U.S. Food and Drug Administration for the quantitative determination of Lp-PLA2 in human plasma, to aid in the prediction of an individual's risk for a coronary event, in conjunction with clinical evaluation and patient risk assessment. The PLA2 test is currently available through laboratories nationwide. For more information about the PLA2 test visitwww.plactest.com. More information about the company may be found at www.diaDexus.com.