OAS1 and viral infectious disease: Increased expression was shown for a number of IFN-stimulated genes such as IFNB1 (interferon, beta 1), IFIT1 (interferon-induced protein with tetratricopeptide repeats 1), OAS1 (2'-5'-oligoadenylate synthetase 1) and MX1 (myxovirus resistance 1, interferon-inducible protein p78), which are involved in cellular defense against viral infection (Fig 6C).