Calcitonin gene related peptide (CGRP) is derived, with calcitonin, from the CT/CGRP gene located on chromosome 11. CGRP is a 37 amino acid peptide and is the most potent endogenous vasodilator currently known.  CGRP is primarily produced in nervous tissue, however, its receptors are expressed throughout the body. CGRP is also strongly implicated in the vasodilatory effect of endogenous cannabinoid anandamide is the brain. This effect was found to be antagonised by capsazepine. CGRP is also currently a major target of research in regards to factors effecting the onset of migrane headaches.