IFNL1, as known as interferon lambda-1, is a secreted protein which belongs to the IL28/29 family. It is a cytokine with immunomodulatory activity. This protein is highly similar in amino acid sequence to the IL28. Also, it plays an important role in host defenses against microbes and its gene is highly upregulated in cells infected with viruses. It may play a role in antiviral immunity. Recombinant human IFNL1, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.