Aspirin (USAN), also known as acetylsalicylic acid (/əˌsɛtəlˌsælɨˈsɪlɨk/ ə-SET-əl-SAL-i-SIL-ik; abbreviated ASA), is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. Aspirin was first isolated by Felix Hoffmann, a chemist with the German company Bayer, under the direction of Arthur Eichengrün.

Salicylic acid, the main metabolite of aspirin, is an integral part of human and animal metabolism. While in humans much of it is attributable to diet, a substantial part is synthesized endogenously.

Aspirin also has an antiplatelet effect by inhibiting the production of thromboxane, which under normal circumstances binds platelet molecules together to create a patch over damaged walls of blood vessels. Because the platelet patch can become too large and also block blood flow, locally and downstream, aspirin is also used long-term, at low doses, to help prevent heart attacks, strokes, and blood clot formation in people at high risk of developing blood clots. It has also been established that low doses of aspirin may be given immediately after a heart attack to reduce the risk of another heart attack or of the death of cardiac tissue. Many people take a daily aspirin to reduce their risk of heart attack. New evidence suggests that aspirin may be a powerful tool in cancer prevention as well.

David Agus (born January 29, 1965) is an American physician and a co-founder of Navigenics, a personal genetic testing company, and Oncology.com, the largest online cancer resource and virtual community and Applied Proteomics. He is a Professor of Medicine and Engineering at the University of Southern California.

He graduated cum laude in molecular biology from Princeton University and received his medical degree from the University of Pennsylvania School of Medicine in 1991. Agus completed his residency training at Johns Hopkins Hospital and completed his oncology fellowship training at the Memorial Sloan-Kettering Cancer Center in New York. He spent two years at the National Institutes of Health as a Howard Hughes Medical Institute-NIH Research Scholar.

Agus has had a long and varied career. At the Memorial Sloan-Kettering Cancer Center in New York, he was an attending physician in the Department of Medical Oncology and head of the Laboratory of Tumor Biology. He was also Assistant Professor of Medicine at Cornell University Medical Center.