Provided below are ELISA kits targeting interferon alpha 21, a human protein encoded by IFNA21. This protein is 189 amino acids long, with a mass of 21.7 kDa, and is a member of the Alpha/beta interferon family. This is reported to be a secreted protein. Other alias names for this protein include: IFN-alpha-21, interferon alpha-F, leukocyte interferon protein, IFN-alphaI, and interferon alpha-F.