Interferon beta 1, also known as IFN-beta, is produced mainly by fibroblasts and some epithelial cell types. IFN-beta is involved in the regulation of unspecific humoral immune responses and immune responses against viral infections. It also increases the expression of HLA class I antigens and blocks the expression of HLA class II antigens stimulated by IFN-gamma. Interferon beta 1 can be used for topic treatment of condylomata acuminata.