There are a number of ELISA Kits available for the measurement of NI220/250, another term for the human protein, reticulon 4. Other synonyms may include: Human NogoA, My043 protein, foocen, neurite growth inhibitor 220, neuroendocrine-specific protein C homolog, reticulon 5, and ASY. It is encoded by the RTN4 gene to yield a protein 1192 amino acids in length and 129.9 kDa in size. However, there are up to 6 reported isoforms. Versions of NI220/250 are present in other organisms, including: Mouse, Rat, Zebrafish, Frog.