IGHE and peanut allergic reaction: On the other hand, the 2S albumins of peanuts, Ara h 2 and Ara h 6, have been shown to be much more potent than Ara h 1 or Ara h 3, an 11S-globulin, for eliciting IgE-mediated mast cell activation in peanut allergy (16, 17, 20–22).