The Prosigna, EndoPredict/EPclin, and Breast Cancer Index assays are capable of identifying low-risk node-positive patients whose prognostic outcomes are favorable; however, these assays have not demonstrated predictive evidence to support withholding adjuvant chemotherapy among higher risk, node-positive, ER-positive, HER2-negative breast cancer patients. This evidence concerns the gene ERBB2 and breast carcinoma.