For example, the siRNA-mediated knockdown of NLRC5 expression in various cell types has shown both enhancement (Cui et al., 2010) as well as the decrease of interferon (IFN) response (Kuenzel et al., 2010), suggesting NLRC5 can act as a positive and negative regulator of IFN response during viral infection. This evidence concerns the gene IFNA1 and viral infectious disease.