Since endogenous interferon produced by the infected cell is not sufficient to eliminate the infection, exogenous recombinant human IFN-α has been therefore used to treat chronic hepatitis C. The cloning and sequencing of functional cDNAs for each interferon has made it possible to use this cytokine as a potential antiviral to treat number of virus infections [34]. This evidence concerns the gene IFNA1 and chronic hepatitis C virus infection.