Edited by
Kim A. Neve

2009

New Opportunities for Drug Discovery

Functional selectivity refers to the observation that different ligands acting at one subtype of receptor that couples to multiple signaling pathways can vary in their ability to activate the signaling pathways; that is, one drug can be an agonist at pathway A and an antagonist or partial agonist at pathway B, and another drug can have the reverse profile. As discussed by Bryan L. Roth in his introductory chapter, this is not a new notion, with evidence for functional selectivity accumulating over the past 20 years.