HuD otherwise known as ELAV-like protein 4 is a protein that in humans is encoded by the ELAVL4 gene. The HuD/ELAVL4 protein is an RNA-binding protein.HuD is expressed only in neurons and it binds to AU-rich element-containing mRNAs. As a result of this interaction the half-life of the transcript is increased. HuD is important in neurons during brain development and plasticity. Monoclonal 15A9 was was generated against a unique HuD peptide and does not react with HuR, HuC, or Hel-N1. Monoclonal 15A9 works well in western blot , IHC and provides an excellent marker for neuronal cells. However, it was specifically selected becasue of it's abiity to supershift HuD/mRNA ribonucleoprotein complexes. Thus, it is the ideal reagent for CHIP or RIP studies to specifically identify novel HuD targets in neuronal cells.