The mammalian type I Inteferons (IFN1) are produced in response to viral infection and other inducers. They are divided into alpha and beta subtypes leukocytes and fibroblasts reactivity. The human IFN alphas are encoded by a family of at least 15 different genes, while IFN beta is the unique member of its subtype. There is approximately 50% amino acid homology between the alpha and beta subtypes. Both IFN subtypes are pleiotropic cytokines and have a similar range of biological activities