Personalized medicine transforms the traditional "one-size-fits-all" model of medicine by utilizing new methods of molecular analysis to better manage a patient’s disease or predisposition toward a disease. It represents a dramatic departure from "evidence-based medicine," which is based on population studies and has dominated medical principles for decades. While the evidence-based approach does allow doctors to modify treatment strategies according to a particular patient's response, it relies on trial-and-error and lacks precision. Personalized medicine, on the other hand, gives doctors an answer based on an individual’s unique set of genes and thereby reduces uncertainty and error in diagnosis and treatment.