The foundation of personalized medicine is Pharmacogenomics - the study of how a person’s genetic inheritance affects the body’s response to drugs. Patients frequently react differently to drugs, independent of other factors such as age or weight. An effective treatment for one person may have no impact on someone else, or may even cause adverse reactions. The main cause of this varying effect is the diversity of humans’ genetic make-up. Personalized medicine tantalizes the public with its promise of providing the right medicine for the right patient at the right dose, saving lives and preventing dangerous side effects.