Provided below are ELISA kits targeting cation channel sperm associated 4, a human protein encoded by CATSPER4. This protein is 472 amino acids long, with a mass of 54.1 kDa, and is a member of the Cation channel sperm-associated (TC 1.A.1.19) family. 2 isoforms have been identified. Other alias names for this protein include: cation channel sperm-associated protein 4, and ion channel CatSper4.