This book is designed to focus on the role of Calcitonin Gene-Related Peptide (CGRP) in health and disease. This peptide, originally discovered in the 1980s as a sensory neuropeptide with cardiovascular effects, is now known to play a distinct role in the pain processing of migraine.  The various chapters address the origin, localization and function of CGRP and its receptor in the peripheral nervous system, in the cardiovascular system, and in other tissues and organs. Further attention is paid to the drug discovery pathway where recent findings show the beneficial effect of small molecule antagonists of the CGRP receptors for the relief of the migraine attack and of monoclonal antibodies against CGRP or the CGRP receptor for migraine prevention.