Additional file 2: Figure S1. of Illness progression in chronic fatigue syndrome: a shifting immune baseline

Site-to-site variability in samples from healthy control subjects. Hotelling’s T squared residual distance separating samples collected in all 3 groups of healthy control subjects from a principal component analysis (PCA) model describing the co-expression patterns linking 16 cytokines. Middle-aged and adolescent groups were statistically comparable (p = 0.839) despite samples being collected at separate sites. (PDF 37 kb