There are a number of ELISA Kits available for the measurement of tachykinin 4 (hemokinin), another term for the human protein, tachykinin precursor 4. Other synonyms may include: tachykinin-4, endokinin, preprotachykinin-C, tachykinin 4 (hemokinin), HK-1, and PPT-C. It is encoded by the TAC4 gene to yield a protein 113 amino acids in length and 12.3 kDa in size. However, there are up to 5 reported isoforms. The protein is categorized into the Tachykinin family.