Also - if you're interested in background on systems biology - there's a broad overview of UCLs biological modelling research group here (http://discovery.ucl.ac.uk/10844/1/10844.pdf [pdf]) - they've got a project modelling the liver / blood-sugar-system.

Apparently the canonical example that has worked pretty well is a computer model of the heart but I think it's a simpler organ in that it's mostly electro-mechanical, without such a complicated chemical system (http://www.sciencemag.org/content/295/5560/1678.abstract - behind Science paywall)