Implementing this approach in allergy research, our group has previously demonstrated, that the transfer of allergen-expressing bone marrow (BM) cells or splenic lymphocytes can induce allergen-specific tolerance and long-lasting (BM cell transfer) or transient (B cell transfer) chimerism preventing the production of allergen specific IgE as well as IgG1 antibodies [19,20]. This evidence concerns the gene IGHE and Allergy.