ACP5 and myalgic encephalomeyelitis/chronic fatigue syndrome: Similarly, patients with TRACP-5b levels ≥ 400 mU/dL demonstrated significantly worse CFS compared with those with levels < 400 mU/dL (median CFS, 63.1 months vs. not reached; HR, 4.98; 95% CI, 1.99–12.45, p < 0.001) (Figure 5B).