Type I interferons (IFNs), IFNα and IFNβ, are crucial and potent components of the early host response against virus infection [2] and recombinant (pegylated) IFNα2a and IFNα2b are widely used for the treatment of CHC and chronic hepatitis B. The current standard treatment of CHC with pegylated IFNα (pegIFNα) and ribavirin leads to cure in about 50% of patients [3], [4]. The gene discussed is IFNA1; the disease is cryohydrocytosis.