A level of specific IgE to Ara h 6 greater or equal than 0.32 kUA/L confirms peanut allergy with 82% sensitivity and 90% specificity, with Ara h 2–specific IgE greater or equal to 0.26 kUA/L improving specificity slightly (94%) with the exact same sensitivity; thus, Ara h 2–specific IgE captures more cases with peanut allergy, and Ara h 6–specific IgE is rarely needed as an additional test for peanut allergy. The gene discussed is IGHE; the disease is peanut allergic reaction.