Both SR and PR allergy symptoms were present in participants: (1) whose serum IgE binding of SR proteins on ELISA examination was inhibited by more than 50% following pre-incubation of the serum with PR proteins; and (2) displayed cross-reactivity between SR and PR owing to the β'-c, and the IgE binding to the SR β'-c was strongly inhibited on immunoblotting following pre-incubation of their serum with PR extract. This evidence concerns the gene IGHE and allergic disease.