Editorial

G-protein coupled receptors (GPCR) are involved in a large variety of physiological and pathophysiological processes. Their fundamental role is highlighted by the fact that of the around 500 currently marketed drugs, more than 30% are GPCR modulators. GPCR agonist and antagonist drugs have therapeutic benefit across a broad spectrum of diseases, including pain (opioid receptor agonists), asthma (β2-adrenoceptor agonists), peptic ulcers (histamine H2 receptor antagonists), migraine (serotonin 5-HT1B/1D agonists), hypertension (angiotensin AT2 receptor antagonists), schizophrenia (serotonin 5-HT2 receptor agonists and dopamine receptor antagonists), rhinitis or allergy (histamine H1 receptor and chemokine receptor antagonists), etc. Besides, no single class of proteins ranks higher than GPCRs in terms of new drug discovery potential. It has been estimated that of the around 400 GPCRs considered to be potential drug targets, only ~30 are targeted by currently marketed drugs. The natural ligand has been identified for a further 210 receptors, which leaves around 160 orphan receptors with no known ligand or function. Without any doubt, therapeutic intervention at these novel receptors will have major benefit in a wide range of human diseases.