A gene fusion network in human neoplasia.

Cancer is, at the cellular level, a genetic disease and acquired gene fusions play a causal role in the initiation of the neoplastic process either by activating proto-oncogenes or creating hybrid genes. We constructed a network by combining the 5' and 3' parts of all presently known gene fusions in human neoplasia and here we show that the observed network is fragmented and that the organization of the genes demonstrates a scale-free network topology with a power law degree distribution meeting the requirements of P(k) approximately k(-gamma), that is, conforming to the distributions found in naturally occurring networks such as the Internet and social or ecological networks. The results hence indicate that the complex system of pairwise interacting genes leading to neoplasia is governed by a universal principle.