Here is the link (click here). Synopsis: Biological networks are highly complex, with many interconnected parts. Yet, network analysis based on small modules has proven highly effective in understanding physiological function. Our paper aims to address, at least in part, why this is the case. We show, through an analysis of the network comprising the cell cycle and pheromone pathways, that bistable switches are part of the answer. In this case, if the cell cycle switch is off, then the pheromone pathways measures the extracellular concentration unperturbed, even when the cell cycle pathway is pushed up to the bifurcation point. However, everything changes when the switch is flipped, as the cell cycle dismantles the pheromone pathway. Thus, the pheromone sensing module is unperturbed by the cell cycle in early G1 and so can be accurately modeled without including the cell cycle phase variable. Anyway, check it out. I think this subject of why motif analysis works is worth exploring since it is really not a priori obvious that it should once you think about how interconnected cellular networks are.