The present invention is directed to the identification of a novel repressor located between ˜1.2 kb to ˜1.6 kb from the translation start site of the IFN-λ1 promoter. The present invention provides a method of using siRNAs against ZEB1 (binds to the repressor region) and BLIMP-1 (binds outside the repressor region) and increases the promoter activity of IFN-λ1 (i.e., increases the production of IFN-λ1 protein). siRNAs against ZEB1 mRNA or BLIMP-1 mRNA increase IFN-λ1 gene activity. There is provided a therapeutic application of siRNAs against ZEB1 and BLIMP-1 mRNAs in treating a mammal (including a human) by increasing the production of IFN-λ1 protein that promotes an anti-viral response as well as treats asthma diseases.