The concept of Erd} os number is well known among mathematicians and somewhat known more generally (see, for example, de Castro & Grossman, 1999] or the web site Paul Erd} os, who died in late 1996, was a mathematician who was author or coauthor|most often the latter|of nearly 1500 papers and had nearly 500 coauthors. By deenition, Erd} os had Erd} os number zero, his collaborators had Erd} os ...

Since the dawn of the post-genomic era a myriad of novel high-throughput technologies have been developed that are capable of measuring thousands of biological molecules at once, giving rise to various "omics" platforms. These advances offer the unique opportunity to study how individual parts of a biological system work together to produce emerging phenotypes. Today, many research laboratories...