Edge betweenness quantified interactions that serve as bottlenecks to various parts of the interaction network39: the paths through ERBB2, such as ERBB2-STAT3 and ERBB2-IQGAP1, have large edge betweenness measures and a functional change in one of these genes could have a cascading effect in different parts of the network, which may relate to the critical role of ERBB2 and STAT3 in epidermal homeostasis and carcinogenesis as well as to their impacts in homeostasis-disrupting cancers of other epithelial tissues40. The gene discussed is IQGAP1; the disease is cancer.