OAS1 and viral infectious disease: Strongly up-regulated genes (greater than eightfold) included interferon-β 1 itself (IFNB1) as well as the interferon-induced IFIT1, IFIT2, and downstream oligoadenylate synthases OAS1, OAS2, and OAS3, akin to a Type-I interferon response triggered by double-stranded RNA (dsRNA) intermediates of viral infection (Karpala et al. 2005).