Heatmaps and confusion matrix for the study group ‘Jena’. Data for the study group ‘Jena’ (that is, utilizing only the probe sets with MAS 5.0 present calls in all samples) were obtained using the Jena patients (10 control group (CG), 10 osteoarthritis (OA), 13 rheumatoid arthritis (RA)) as the training set for the rule generation and re-applying the respective rules to the same dataset. (A) Heatmap of the membership weights applying all rules of the primary rule set (α = 0.94; ‘CG’, 31 rules; ‘OA’, 10 rules; ‘RA’, 20 rules) for the prediction of the clinical status of the different samples; dashed red lines indicate the lower limits of the respective pruned lists of rules subsequently applied in (B). (B) Heatmap of the membership weights applying pruned lists of rules (α = 0.94; ‘CG’, nine top-ranked rules; ‘OA’, 10 top-ranked rules; ‘RA’, 10 top-ranked rules) for optimized prediction of the clinical status of the different samples. (C) Confusion matrix for the rule set displayed in heatmap (B). TP, true positives; TN, true negatives; FP, false positives; FN, false negatives.