CD4 and allergic disease: The loading of this pocket of BLG has a decisive influence on the development of allergy: unloaded BLG, so-called apo-BLG, promotes the increase of CD4+ T cells as well as the expression of Th2 cytokines and subsequently allergies and inflammation, whereas BLG loaded with ligands (holo-BLG) suppresses CD4+ T helper cells in vivo and in vitro, and thus has immunosuppressive effects [21, 32, 33].