IFNA1 and systemic lupus erythematosus: Since polymorphisms in genes that are part of the signaling pathway of Type I IFNs, such as IRF5, IRF7, and STAT4, are associated with a higher risk of developing SLE (Harley et al., 2009), the over-expression of Type I IFNs in these patients may be the result of the combination of genetic predisposition to produce high levels of Type I IFNs and exposure to danger signals that stimulate IFN production (Elkon and Stone, 2011; Niewold, 2011).