The first complete genome sequence of a multicellular organism, Caenorhabditis elegans, has been determined recently. Several more will follow soon, among them the genome sequences of Drosophila melanogaster and the human. With these achievements, the stage is set for the next phase of "large-scale" biology, the study of the function of genes and the interactions between their protein products. The aim of the Ernst Schering Research Foundation Workshop 29 was to discuss the contribution of research on model organisms which are particularly suited for genetic and biological research, to the...