ABSTRACT
Interferons (IFNs) are naturally occurring proteins that have a wide variety of antiviral, antiproliferative, and immunomodulatory effects. They act in a relatively nonspecific manner to inhibit viral infection. There are three classes of interferons: interferon alpha (multiple subtypes), interferon beta, and interferon gamma. Interferon alpha and beta are primarily antiviral, whereas interferon gamma is primarily immunomodulatory. Only interferon alpha has been used to treat viral infections.
