Expressed on Aδ and C afferent fibers, TRPA1 transduces pain from a broad array of irritants, both food (e.g., allyl isothiocyanate in mustard) and chemical (e.g., formaldehyde) and is thought to be implicated in the pathogenesis of headache [23,26]. The gene discussed is TRPA1; the disease is Headache.