Figure 3
From: Association study based on topological constraints of protein–protein interaction networks
Association Z-scores of random gene sets and statistical validation of cutoffs. (a) Heat map of association Z-scores among 50 randomly constructed gene sets with gene numbers in the range of [15,200]. (b) Histograms of association Z-scores calculated from five sets of random networks (see Methods and Figure S2 in the SI). Among all 15,000 Z-scores between random gene sets, 451 have Z > 2 (P = 0.030) and 160 have Z < − 2 (P = 0.011), respectively, indicating that using |Z|> 2 as the cutoff would be appropriate. (c) Network of the random gene sets weighted by the association Z-scores. A cutoff of |Z|> 2 is used for both enhanced (red) and suppressed (blue) interactions. (d) We then bootstrapped the affiliations of all genes from the two randomly constructed gene sets, each contains 100 genes. The association Z-score of the original pair is − 0.14 (red arrow) whereas the Z-score of the 1,000 bootstraps are − 0.47 ± 0.66.
