CCL20 and myalgic encephalomeyelitis/chronic fatigue syndrome: Using IVW method, we found that higher levels of TNF were associated with a decreased risk of ME/CFS (OR: 0.97; 95% CI: 0.94–0.99; p = 0.007), while increased levels of CXCL5 (OR: 1.02; 95% CI: 1.00–1.03; p = 0.04) and CCL20 (OR: 1.03; 95% CI: 1.00–1.05; p = 0.02) were associated with an elevated risk of ME/CFS (Figure 3).