FCGR2B and allergic disease: The human subjects carrying rare FcγRIIB-Thr allele produced significantly more IgE (P = 0.0002 for 187Ile/Thr heterozygous subjects and P = 0.0004 for 187Thr/Thr homozygous subjects) than those homozygous (187-Ile/Ile) subjects carrying the common allele, suggesting that the functional FcγRIIB SNP may have a role in allergy through IgE production.