TNF and myalgic encephalomeyelitis/chronic fatigue syndrome: Comparing CFS patients with longer duration of illness to the control group, showed that CFS patients had lower levels compared to controls for TGF-β1, TGF-β2, and TGF-β3 (p ​= ​.005, p ​< ​.001, and p ​= ​.004, respectively), but these patients could no longer be distinguished from controls on TNF-α and IL-10 (p ​= ​.073 and p ​= ​.673, respectively).