Moreover, poly(I:C) also increased brain and skin gene expression of TNF-α, IL-6, KC, CCL2, CCL4, CCL5, CXCL10, while HDC and NT gene expression were only increased in the skin, suggesting that NT and histamine may explain the skin findings in CFS patients. The gene discussed is CCL4; the disease is myalgic encephalomeyelitis/chronic fatigue syndrome.