Contacts:

Sharon Tetlow Vice President, Chief Financial Officer diaDexus 650-246-6400 stetlow@diadexus.com

DIADEXUS NAMES JACQUELINE PAPKOFF, PH.D. VICE PRESIDENT OF DISCOVERY

South San Francisco, CA - March 5, 2002 - diaDexus today announced the appointment of Jacqueline Papkoff, Ph.D., as Vice President, Discovery. Dr. Papkoff joins diaDexus from Aventis Cambridge Genomics Center (previously Hoechst-Ariad Genomics Center), where she served as Vice President of Cell Biology and Genetics and Head of Genomics Platform Technologies.

"We are pleased that Dr. Papkoff has joined diaDexus to lead our scientific discovery efforts," said Ronald M. Lindsay, Vice President, Research and Development and Chief Science Officer of diaDexus. "Her significant expertise in oncology research will be instrumental in guiding the company's discovery and development in this key focus area."

At the Aventis Cambridge Genomics Center, Dr. Papkoff was responsible for the cell biology and functional genomics programs and subsequently for core research and production technologies, including high throughput sequencing, full-length cloning, cDNA libraries, vector development, gene expression profiling, new profiling technologies, genetic screens, cell-based functional validation and pathway validation.

Prior to her tenure with Aventis, Dr. Papkoff served as Director of Molecular Oncology for Megabios Corporation and before that served as Senior Scientist in Sugen Inc.'s Department of Cellular Biochemistry. She also held several research scientist positions at Syntex Research.

Dr. Papkoff has been a Consulting Professor of Cancer Biology with Stanford University for 10 years. She received her B.A. in Biology from the University of California, Santa Cruz, a Ph.D. in Biology at the Salk Institute from the University of California, San Diego and completed postdoctoral research at Stanford University and the University of California, San Francisco.

About diaDexus
diaDexus, 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. diaDexus has utilized genomics and bioinformatics to identify thousands of disease-associated molecular targets. Currently, diaDexus has three diagnostic product candidates in late-stage pre-clinical development. For more information, please visit www.diaDexus.com.

The statements in this press release which are not historical facts or information may be forward-looking statements. These forward-looking statements involve risks and uncertainties that could cause the outcome to be materially different from the outcome described in these forward-looking statements.