ERBB2 and neoplasm: The nine-gene panel was a more reliable predictor of 2 years DSS in the TCGA (AUC = 0.806), METABRIC (AUC = 0.706), and GSE3494 cohorts (AUC = 0.624) (Figures 3D–F) because it had a high predictive accuracy for DSS, which was even better than those of the statuses of ER, PR, HER2, and lymph nodes as well as tumor size (Figures 4A,B).