TNF and myalgic encephalomeyelitis/chronic fatigue syndrome: Juel and colleagues [55, 56] examined the production of NF-κB P50 in unstimulated 10 ng/mL TNF-α and 50 ng/mL PMA (phorbol 12-myristate 13-acetate, PMA) stimulated peripheral blood lymphocytes in 18 CFS/ME patients and 18 age-matched controls.