[42] The hub designation itself, however, is somewhat arbitrary. For clarity, hubs are defined here as proteins that are in the top ∼20% of the degree distribution or in other words, proteins that have the ∼20% highest number of neighbors. Based on this criteria, Rac1, Cdc42, RhoA, and HRas are the hubs identified in the small GTPases network. These GTPases have multiple cellular roles that involve the regulation of cytoskeleton dynamics and cell growth processes and are strongly associated with human cancers [12], [13]. The gene discussed is CDC42; the disease is cancer.