SANTA CLARA, Calif.--DiaDexus, a new company here formed as a joint venture between SmithKline Beecham and Incyte Pharmaceuticals and dedicated to the discovery and commericalization of novel molecular diagnostic products, announced the appointment of William Gerber to the post of president and CEO. Gerber joined DiaDexus from Onyx Pharmaceuticals where he was vice-president and chief operating officer. Previous to that, Gerber was president of Chiron Diagnostics, held various positions with Cetus, and was a practicing physician.