Abstract

Some patients tolerate a given drug well, without adverse reactions. For others, though, an identical dose of the same medication can have toxic effects. Moreover, while a drug can be effective at relieving symptoms for some patients, it may fail to do the same for others suffering with the same disease. With such variability in treatment responses, tailoring medical interventions to individual patients has long been an aspiration of medicine. Until recently, however, medicine lacked a clear understanding of the biological reasons for human variation in drug response. Attempting to adjust treatment to the individual patient, physicians have relied primarily on direct observation, trial-and-error, and, ultimately...