Other well documented immune abnormalities in ME/CFS, which are not germane to sickness behavior, include dysregulated forkhead box P3 (FoxP3) expression [119], disrupted T cell homeostasis as indicated by reports of increased CD26 expression [120], decreased expression of CD69 [121] and elevated B cell numbers [122]. This evidence concerns the gene FOXP3 and myalgic encephalomeyelitis/chronic fatigue syndrome.