Provided below are ELISA kits targeting follistatin like 4, a human protein encoded by FSTL4. This protein is 842 amino acids long with a reported mass of 93.1 kDa. 3 isoforms have been identified. This is reported to be a secreted protein. Glycosylation sites have been reported. Other alias names for this protein include: follistatin-related protein 4, and follistatin-like protein 4. ELISA kits are available that are reactive to human, mouse, and rat variants of the target antigen.