To understand genetic factors that might influence the risk of developing food allergy, a genome-wide association study evaluated major histocompatibility II genes in 2,759 United States (US) participants of European ancestry from the Chicago Food Allergy Study with food allergy (defined as a history of an allergic reaction after ingestion of peanut, egg, or milk and food sensitization to the same food [food-specific immunoglobulin E (IgE) ≥ 0.10 kU/L and/or skin prick test mean wheal diameter ≥3 mm]) (3). This evidence concerns the gene IGHE and food allergy.