HuD, otherwise known as ELAV-like protein 4 or PNEM, is a protein that in humans is encoded by the ELAVL4 gene. This human gene is located at 1p34 by in situ hybridization. The HuD/ELAVL4 protein is anRNA-binding protein. ELAVL4 has specificity for 3-prime uridylate-rich untranslated regions of growth factor mRNAs. And HuD is expressed only in neurons and it binds toAU-rich element-containing mRNAs. As a result of this interaction the, half-life of the transcript is increased. Also, HuD is important in neurons during brain development and plasticity.