Contacts:

Sharon Tetlow diaDexus 650-246-6400 stetlow@diadexus.com

DIADEXUS EXCLUSIVELY LICENSES RIGHTS RELATED TO TESTISIN, A NOVEL SERINE PROTEASE CANCER TARGET, FROM QUEENSLAND INSTITUTE OF MEDICAL RESEARCH

South San Francisco, CA - February 12, 2003 - diaDexus, Inc., announced that the company has exclusively licensed rights related to a novel cancer target, Testisin, from the Queensland Institute of Medical Research (QIMR), Queensland, Australia. diaDexus will have the exclusive right to develop and commercialize therapeutic and diagnostic products targeting Testisin, a novel cell surface-associated serine protease.

"Research performed at diaDexus has associated increased levels of Testisin with ovarian cancer," said Ron Lindsay, Ph.D., Chief Science Officer of diaDexus. "This license secures our right to develop products involving this protein." Financial terms of the arrangement were not disclosed.

diaDexus, 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. diaDexus has utilized genomics and bioinformatics to identify numerous disease-associated molecular targets. For more information, please visit www.diaDexus.com.