  Cooperation played a significant role in the self-organization and evolution
of living organisms. Both network topology and the initial position of
cooperators heavily affect the cooperation of social dilemma games. We
developed a novel simulation program package, called 'NetworGame', which is
able to simulate any type of social dilemma games on any model, or real world
networks with any assignment of initial cooperation or defection strategies to
network nodes. The ability of initially defecting single nodes to break overall
cooperation was called as 'game centrality'. The efficiency of this measure was
verified on well-known social networks, and was extended to 'protein games',
i.e. the simulation of cooperation between proteins, or their amino acids. Hubs
and in particular, party hubs of yeast protein-protein interaction networks had
a large influence to convert the cooperation of other nodes to defection.
Simulations on methionyl-tRNA synthetase protein structure network indicated an
increased influence of nodes belonging to intra-protein signaling pathways on
breaking cooperation. The efficiency of single, initially defecting nodes to
convert the cooperation of other nodes to defection in social dilemma games may
be an important measure to predict the importance of nodes in the integration
and regulation of complex systems. Game centrality may help to design more
efficient interventions to cellular networks (in forms of drugs), to ecosystems
and social networks. The NetworGame algorithm is downloadable from here:
www.NetworGame.linkgroup.hu
