Ara h 1 is a seed storage protein from Arachis hypogaea (peanuts). It is a heat stable 7S vicilin-like globulin with a stable trimeric form that comprises 12-16% of the total protein in peanut extracts. Ara h 1 is known because sensitization to it was found in 95% of peanut-allergic patients from North America. In spite of this high percentage, peanut-allergic patients of European populations have fewer sensitizations to Ara h 1.