Receiver operator characteristic (ROC) curves from single assays for amphiregulin (AmR), epidermal growth factor (EGF), heparin binding epidermal growth factor (HB-EGF), matrix metalloprotease 9 (MMP9), and RANTES, all of which are significantly altered in patients with breast cancer in subjects with either ER+/HER2- tumors (left column) or ER-/HER2+ tumors (right column). Each graph contains step (empirical) and smooth (fitted, parametric) ROC curves, and a grey shaded area that presents the 90% confidence intervals of the fitted curve, as generated by Monte Carlo analysis.