CD40LG and myalgic encephalomeyelitis/chronic fatigue syndrome: We recently described significantly increased frequency and expression of CD24 on subsets of IgD+IgM+ B cells from patients suffering from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) (16), a multisystem disorder characterized by fatigue, post-exertional malaise and cognitive impairment (17, 18).