PhospoPep version 2.0 is a project to support systems biology signaling research by providing interactive interrogation of MS-derived phosphorylation data from 4 different organisms. Currently there is data from the fly (Drosophila melanogaster), human (Homo sapiens), worm (Caenorhabditis elegans), and yeast (Saccharomyces cerevisiae). The experimental data was collected and analyzed by the Aebersold group at the Swiss Federal Institute of Technology (ETH) in collaboration with the Functional Genomics Center ( FGCZ ) in Zurich, Switzerland, and the Institute for Systems Biology (ISB) in Seattle, Washington USA.