Evaluation of network-based heuristics by frequency domain analysis. Correlation of minimum distance (black) and weighted network distance (red) with measured perturbation of the cell cycle. A Perturbation by p53a. B Simultaneous perturbation by p53a and NF-κBn. C Perturbation by NF-κBn. R2 is the coefficient of determination and indicates the ability of the heuristic to predict the measurement: R2 = 1 is perfect; R2 = 0 shows no ability.