IFNA1 and systemic lupus erythematosus: Thus, while increased levels of IFN-II and IFN-II + IFN-III are the most prevalent IFN types in SLE, the data point to a model in which the co-elevation of IFN-II and IFN-III creates a low disease activity environment that is amplified by the addition of IFN-I, acting as the determinant to evolve to a more severe disease.