Transcription Factor Protein (IMAGE) University of Pennsylvania School of Medicine Caption Localization of Elk-1 protein in neuronal dendrites. Elk-1 appears in red. Credit (Credit: Lindy Barrett, PhD and Jai Yoon Sul, PhD, University of Pennsylvania School of Medcine, and Nature Methods, June 2006) Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.