IFNA1 and viral infectious disease: By studying the effects of IFN-α released from plasmacytoid dendritic cells on Th-responses in SLE, Seventer and co-workers [13] proposed a pathogenic role for IFN-α in the triggering of the disease, whereas in established disease, and in chronic viral infections with continued type I IFN activation, IFN-α rather inhibits development of proinflammatory Th responses [13].