Chiron was founded when three prominent university professors left the biochemistry departments of the Bay Area's leading universities to start a company dedicated to developing and commercializing a new generation of diagnostic, therapeutic and vaccine products. The three founders, William Rutter, Edward Penhoet and Pablo Valenzuela shared a common vision - to use the emerging tools of biotechnology to create products that would transform the practice of medicine and improve the quality of life by diagnosing, preventing and treating human disease. Chiron originally focused its expertise on the development of vaccines and tests for infectious diseases, mainly hepatitis. The company, along with scientists at University of California, San Francisco, developed and licensed the key ingredient used in Recombivax HB®, Merck's hepatitis B vaccine. Following their work on hepatitis B, Chiron scientists cloned the hepatitis C virus (HCV). Chiron has also cloned and sequenced the entire genome of HIV, enabling scientists around the world to study the structure of this deadly disease and helping them to develop more effective treatments and vaccines. As Chiron evolved, the company expanded its areas of concentration to include cancer, immune deficiencies, and cardiovascular diseases. Through its 1991 merger with Cetus, Chiron acquired Proleukin® (aldesleukin), an immune system stimulator that is marketed for the treatment of metastatic kidney cancer and metastatic melanoma. Today, studies are underway to test the effectiveness of Proleukin in patients with various types of cancer and infectious diseases. The company was acquired by Novartis in April 2006 and is now focused on Nucleic Acid Testing for blood screening.