The process of core hopping and the final agonists' structures thus selected are illustrated in Fig. 2 , from which we can see the following. The structure of GW409544, which is conceived as an agonist model to develop novel therapeutic agents for treating metabolic disorder, may be divided into three parts, Core A, Core B, and Core C, as marked by dash lines. Considering the great importance of the acidic head in Core A for activating PPARs receptors, let us retain the Core A part during the core hopping calculation as described below.