IL6 and myalgic encephalomeyelitis/chronic fatigue syndrome: Similarly Gaab et al. (2005) [18] (n = 10 male and 11 female; age 36 years [30–47 years]) observed a positive correlation between fatigue and LPS-induced in vitro production of TNFα in CFS and with IL-6 in both CFS and control subjects though expression levels were found to be comparable.