IFNA1 and infection: Next, HIV-infected cell cultures were directly stimulated with two different concentrations (325 U/mL and 2,000 U/mL) of parental IFNα2, IFNα14, or IFNα2-mutants and the IFN-mediated effects on viral loads were analyzed 3 days post infection (dpi) (Fig. 4B through E).