The general reliability framework to study gene interaction is incredibly straightforward. It is a general mixture model of parallel and serial configuration.
S' = S'_parallel * phi + S'_serial * (1-phi)
or
S = S_parallel * phi + S_serial * (1-phi)
where phi is the mixing weight.
Thia framework can be used to test whether a gene can have broad network influence or a local influence. For example, TOR1 has been shown to activate ribosomal protein S6 kinase (S6K), and have a broad impact on protein networks. So, modeling the net' and X for tor1D, wildtype and compare them with AIC can be useful.
The mixing parameter $\phi$ is informative a gene's function.
See
http://en.wikipedia.org/wiki/Mixture_model
