The fluid in skin blisters and peripheral blood of herpes zoster patients has low levels of the Th1 cytokines interleukin (IL)-2 and tumor necrosis factor-α and high levels of the Th2 cytokines IL-10 and IL-4 compared with the levels of these cytokines in samples from a control group [23]. The gene discussed is TNF; the disease is herpes zoster.