Network diagrams for A) participants with CFS and B) healthy controls. A network diagram of fatigue and 51 cytokines was constructed in NodeXL. All participants were included in the analysis. Fatigue and leptin are highlighted in red, and variables with significant correlations with fatigue and leptin are represented by red edges (A). The network diagram was thresholded at p < 0.0012, false discovery rate controlled for multiple comparisons.