Applications in Pharmacogenetics are breaching the laboratory medicine and clinical environment. The testing of genetic variations in relation to differing response to drug metabolism and improvement of drug safety is an important and essential area in light of adverse drug reactions. This timely and comprehensive issue of the Clinics presents topics related to Pharmacology and Genetics, Pharmacogenetic Applications in Anticoagulation, Oncology, Pain Management, and Behavioral Disorders, Respiratory Disorders, as well as Education and Healthcare Economics of Pharmacogenetics.