were then grouped according to the Anatomical Therapeutic Chemical class of the drug41. Only drug classes with at least 10 valid drug gene sets within them were analyzed. Drug-class analysis was performed using enrichment curves. All drug gene sets were ranked by their association in the drug set analysis, and then for a given drug class an enrichment curve was drawn scoring a “hit” if the drug gene set was within the class, or a “miss” if it was outside of the class. The area under the curve was calculated, and a P-value for this calculated as the Wilcoxon Mann-Whitney test comparing drug gene sets within the class to drug gene sets outside of the class41. Multiple testing was controlled using a Bonferroni-corrected significance threshold of P < 5.60 × 10−5 for drug-set analysis and P < 7.93 × 10−4 for drug-class analysis, accounting for 893 drug-sets and 63 drug classes tested.
