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. This evidence concerns the gene CCL5 and myalgic encephalomeyelitis/chronic fatigue syndrome.