Although CpG is known as a Th1-immunity inducer, CpG could decrease Th2 immunity in airway allergy without inducing strong Th1 immunity or Th1 cytokines15, 19, 21; for example CpG could promote the expression of MHC II, CD80 and CD86 on DCs which can then activate T cells and skew them away from a Th2 phenotype independently from IFN-γ. Here, IFNG is linked to allergic respiratory disease.