Fig. 5. Attractor landscape representation of cell fate determination. A hypothetical `potential landscape' that represents the n-dimensional state space compressed into two dimensions (XY) for visualization purposes. Every position in the XY plane would correspond to a network state (e.g. expression profile of gene and protein activities). The vertical axis (Z) represents a potential function, an `energy equivalent', representing some distance measure of a network state to the attractor state. Lowest points in the valleys correspond to attractor states that represent cell fates. Yellow arrows indicate a path that takes the cell from growth to apoptosis.