Typical reaction cycle with input fluxes. The in-fluxes Ji result from indirect interactions between processes of different layers. As the processes are assumed to be independent, the rates d1 and d3 are parametrized by k1 and k-1. Additionally, the rates d2 and d4 are parametrized by k2 and k-2.
Koschorreck et al. BMC Bioinformatics 2007 8:336 doi:10.1186/1471-2105-8-336