The IFN-β proteins are produced in large quantities by fibroblasts. They have antiviral activity that is involved mainly in innate immune response. Two types of IFN-β have been described, IFN-β1 (IFNB1) and IFN-β3 (IFNB3)[5] (a gene designated IFN-β2 is actually IL-6). IFN-β1 is used as a treatment for multiple sclerosis as it reduces the relapse rate. IFN-β1 is not an appropriate treatment for patients with progressive, non-relapsing forms of multiple sclerosis.
In mice, IFN-β inhibits immune cells to produce growth factors, thereby slowing tumor growth, and inhibits other cells from producing vessel producing growth factors, thereby blocking tumor angiogenesis and hindering the tumour from connecting into the blood vessel system.