GPCRs are the largest group of signal transducing transmembrane proteins, constituting roughly 4% of the proteincoding genome. They play integral roles in a wide range of biological pathways from response to sensory inputs (gustatory, olfactory, and visual) to cell growth, and cardiovascular and immune system regulation. They have also been implicated in a wide variety of diseases, such as autoimmune diseases, cancer, as well as metabolic, cardiovascular, and neurologic disorders. With their ability to demonstrate high specificity and affinity for their ligand, GPCRs are a crucial target for drug discovery. Furthermore, there are still many GPCRs considered orphan receptors, which are GPCRs whose interacting ligand has not yet been discovered.