The key to good drug design is working out and capturing the clinical spectrum of disease and the exact role a potential therapeutic target plays in the disease. In the words of the German researcher, Paul Ehrlich, known for his countless contributions to the field of pharmacology, “corpora non agunt nisi fixate” - drugs will not act unless they are bound.1 The Oxford Dictionary of Biochemistry and Molecular Biology defines a drug target as “a biological entity (usually a protein or gene) that interacts with, and whose activity is modulated by, a particular compound.”This article highlights the properties of an attractive drug target, outlines the approaches used to identify targets, and discusses the key steps involved in target validation and the benefits and challenges of using siRNA to validate targets. a target is termed ‘druggable’ if its activity (behavior or function) can be modulated by a therapeutic – whether it be a small molecule drug, or biologic. Proteins and nucleic acids are both examples of biological targets