Taken together, these data suggest that in MS cases with oligoclonal band positive CSF there is a cytokine profile characteristic for a Th1 immune response [IFNγ and IL-12(p40)] and granulocyte activation (CXCL1 and G-CSF), whereas in CFS negative for oligoclonal IgG there is a lack of the Th1 response, as well as an absence of granulocyte activation. The gene discussed is IFNG; the disease is myalgic encephalomeyelitis/chronic fatigue syndrome.