Table 1 Properties of E. coli and S. cerevisiae networks. This table compares the charactistics of E. coli and S. cerevisiae source networks which are used in the creation of subnetworks. The extended E. coli network described by Ma et al.  has over three times more nodes than the E. coli network described by Shen-Orr et al. . The average path length is longer for this network and the average clustering coefficient is higher. For rigorous definitions of the measurements see additional file 1: addendum.pdf.