Although IFN-λ1 has been found to play a critical role in host defense against microbes and virus infection, one study showed that IFN-λ1 downregulated adipogenic markers, including peroxisome proliferator-activated receptor-γ (PPAR-γ), FABP-4, and lipoprotein lipase, in mature SGBS adipocytes. Here, IFNL1 is linked to viral infectious disease.