Pharmacogenomics is an important example of the field of precision medicine, which aims to tailor medical treatment to each person or to a group of people. Pharmacogenomics looks at how your DNA affects the way you respond to drugs. Pharmacogenetics deals with the differences in effect of drugs caused by genetic variation. Genetic variation in metabolism may result in high concentrations of drugs and an increased risk of adverse effects in slow metabolizers, which is important when using for example antidepressants or chemotherapy.