IGHE and allergic disease: Because Ara h 6 binding IgE was frequently presented in PNA, but monosensitization of Ara h 6 IgE was rarely found, it was likely that in the real PNA settings, Ara h 6 mainly functioned as a potent cross-reactor to trigger Ara h 2 IgE-mediated peanut reactivity but not necessarily triggering Ara h 6–specific IgE-mediated peanut allergic reactions.