Biological networks play a crucial role in solving complex biological problems in the life sciences. Modern wet lab techniques such as GC/MS, multidimensional protein gels, and microarrays produce a continuously increasing amount of biological data sets. These arise from different domains such as metabolomics, proteomics, and transcriptomics. In order to achieve aims of life science projects such as the invention of new drugs or the increase of yield in crop plants, a deep understanding of the complex interactions of biological entities from different domains is necessary.