MMSE scores were recorded at the time of plasma acquisition at the respective clinical centers. Scores were available for 44/47 AD patients and 26/52 Control patients (Additional file 2 and Additional file 1: Table S1). MMSE scores were correlated to Z-scored protein levels using Spearman’s rank correlation. Correlation significance was assessed using Spearman’s p-value (pRho: significance that slope is not 0) and by computing an empirical p-value by permuting protein scores over MMSE scores 1,000-times (pPerm: Number of times that random MMSE-Protein data yields correlation greater than observed/1,000). Network representation was performed as described above.