Fig. 2

a Principal component analysis of the study group proteomic data. Scores for PC1 (38.5%) versus PC2 (15.9%), Sqrt/Pareto. The nine age- and gender-matched healthy control subjects grouped close together, distinct from a large subgroup of nine (P1, P2, P3, P4, P5, P6, P7, P8, and P9) of the eleven ME/CFS subjects. b Principal Component logistic regression after leave-one-out cross-validation classified 10 out of 11 patients correctly as patients and 7 out of 9 controls correctly as controls. Patient P10 and controls C3 and C5 were misclassified