The 90-gene meta-signature displayed greater performance than nodal status in predicting relapse-free survival in breast cancer, and it further predicts survival outcome in nodal status sub-cohorts. (A) Lymph node status correlates with survival outcome (P = 0.0004). (B) The meta-signature correlates with survival outcome (P = 2 × 10-10). (C) The meta-signature differentiates risk groups in nodal negative patients (P = 2.6 × 10-5). (D) The meta-signature predicts risk groups in nodal positive patients (P = 7.0 × 10-5).