Pharmacogenomics is a field of research that studies the role of genome in drug response. It involves the study of how genes affect a person's response to drugs. This field integrates pharmacology with genomics to develop effective, safe medications that may be prescribed based on a person's genetic makeup. There are several factors, such as a patient's age, weight, sex, and liver and kidney functions based on which the drugs are prescribed. Researchers have identified gene variants for a few drugs that affect the body's response to medications. These genetic variations are used to predict whether a medication will be effective for a particular person, and which dose will help in preventing adverse drug reactions. Pharmacogenomics may also be used to develop tailored drugs to treat a wide range of diseases, such as cardiovascular disease, Alzheimer disease, cancer and asthma. This book contains some path-breaking studies in the field of pharmacogenomics. It will serve as a valuable resource for scientists, students, and clinicians engaged in pharmacogenomics research and therapeutic implementation.