Fig. 1.

Waddington’s epigenetic landscape from a systems pharmacology perspective. Lines represent the trajectories of the ball towards valleys. Valleys are represented as attractors of normal proliferation, aberrant proliferation, or apoptosis. The unperturbed network (right) is representative of a trajectory towards a healthy normal attractor (blue), whereas a network that has gained mutations in specific nodes (left) is representative of a trajectory towards a neoplastic attractor (red). Yellow bolts indicate nodes that have been mutated. A pharmacological intervention (purple) may shift the trajectory towards one that is favorable, whether it is back towards normal proliferation or apoptosis. Adapted from [43].