IFNA1 and hepatitis C virus infection: For GT1-infected patients who had failed previous PI-NS5A inhibitor therapy, sofosbuvir-ledipasvir was the only IFN-free DAA regimen recommended in the 2016 JSH guidelines for the management of hepatitis C virus infection and only if the virus did not harbor multiple polymorphisms at positions 31 plus 93 in NS5A (10).