diaDexus (DDXS.OB) is a medical diagnostics company, located in South San Francisco, California, focused on the development and commercialization of patent-protected in vitro diagnostic products addressing significant unmet needs in cardiovascular disease.diaDexus' first product, the PLAC Test helps identify individuals at increased risk of suffering a heart attack or stroke, the #1 and #3 causes of death respectively in the U.S. These events can be prevented through early detection and more aggressive risk-reducing strategies.