How many drug targets are there?

Abstract
For the past decade, the number of molecular targets for approved drugs has been debated. In this article and the accompanying poster, Overington and colleagues provide a comprehensive survey of current drug targets and a wealth of associated information on the characteristics of target families and the drugs that modulate them. For the past decade, the number of molecular targets for approved drugs has been debated. Here, we reconcile apparently contradictory previous reports into a comprehensive survey, and propose a consensus number of current drug targets for all classes of approved therapeutic drugs. One striking feature is the relatively constant historical rate of target innovation (the rate at which drugs against new targets are launched); however, the rate of developing drugs against new families is significantly lower. The recent approval of drugs that target protein kinases highlights two additional trends: an emerging realization of the importance of polypharmacology, and also the power of a gene-family-led approach in generating novel and important therapies.