Kaplan-Meier plots of the pooled breast cancer datasets, both unstratified (A) and stratified (B). (A) As with the unpooled results, positive E2F4 scores (red curve) show shorter survival times than those with negative E2F4 scores (green curve) across all datasets (P value = 1.43e-21, log-rank test). (B) After stratification by pharmacological treatment (top two plots) or the Adjuvant! composite clinical risk score (bottom two plots), E2F4 iRASs remain predictive of survival prognosis within each stratum (all P values <0.001). Vertical hash marks indicate points of censored data. Survival endpoint is relapse-free survival (RFS) as indicated on the vertical axes. iRASs, individual regulatory activity scores.