The proportion of patients with high levels (> 0.35 kU/L) of specific IgE to cefaclor was also significantly higher in patients with anaphylaxis (153 in 236) than in patients with non-anaphylactic immediate HS (28 in 97) (64.8% vs. 28.9%, P < 0.001). The gene discussed is IGHE; the disease is anaphylaxis.