Estimation of differences of serum proteome patterns between sub-groups of breast cancers patients. Patients were differentiated by age, primary tumor size (T), lymph nodal status (N), histopathological grade (G), and estrogen (ER) and progesterone (PR) receptor expression. A – The total error rates of classification plotted against the number of features in the classifiers as in Fig. 1A; the actual line width corresponded to 95% confidence intervals. B – ROC curves computed for classifiers built of 15 spectral components for each comparison (computation was done as described in Fig. 1B).