Below are ELISA kits for the investigation of ENK, another term for proenkephalin. In humans this protein is encoded by the gene, PENK. The gene is also conserved in other species, including: mouse, rat. This 267-amino acid secreted protein is a member of the Opioid neuropeptide precursor family. Other names for this protein may include: preproenkephalin. For more detailed ELISA target information, visit the supplier page.