Mark Estelle received his Ph.D. in Genetics at the University of Alberta in 1983 where he worked on the regulation of gene expression in Drosophila. After postdoctoral work with Chris Somerville at Michigan State University, he established his own lab at Indiana University studying the important plant hormone auxin. He is now the Tata Chancellor’s Endowed Professor in Cell and Developmental Biology at the University of California San Diego. Mark Estelle’s lab continues to explore the mechanism of auxin action as well as the role of ubiquitin-dependent protein degradation in cellular regulation. His research group uses the genetically tractable plant Arabidopsis thaliana to identify key proteins in auxin signaling including the auxin receptor. His recent work is focused on understanding the specificity of auxin response in different cellular contexts.