IL6 and myalgic encephalomeyelitis/chronic fatigue syndrome: The IL-6 mRNA expression in conjunctiva correlated well with OSDI score (R = 0.53, P<0.001; Fig 4E), Schirmer I test (R = -0.68, P<0.001; Fig 4F), BUT (R = -0.81, P<0.001; Fig 4G) and CFS score (R = 0.86, P<0.001; Fig 4H).