Michael Eisen is a professor of Genetics, Genomics, and Development in UC Berkeley's Department of Molecular Biology, and an investigator with the Howard Hughes Medical Institute. Research in the Eisen Lab is motivated by a desire to understand the molecular basis of phenotypic variation within and between species, and is driven by the belief that many differences in physiology, morphology and behavior arise from changes in how genes are turned on and off during the developmental transformation from a fertilized egg to an adult organism. The lab employs a combination of experimental and computational methods to the study of gene regulation, using the fruit fly Drosophila melanogaster as a model system. Eisen and his colleagues have pioneered genomic approaches in modern molecular biology and are leaders in the emerging field of computational biology. In addition to his lab work, Eisen is a long-time advocate for "open science." In 2001 he co-founded the Public Library of Science (PLoS), a San Francisco non-profit dedicated to making the worlds scientific and medical literature a freely available public resource. PLoS is now the leading publisher of "open access" journals, and through PLoS and other ventures Eisen continues to play a major role in the open-science movement.