TNF and parasitic infectious disease: Th1 cells are chemokine receptor CXCR3+ lymphocytes bearing the T-box expressed in T cells (T-bet) transcription factor, secrete interferon (IFN)-γ, tumor necrosis factor (TNF)-α and interleukin (IL)-2, and eradicate intracellular pathogens; conversely, Th2 lymphocytes express GATA-3 transcription factor and the chemokine receptor CCR4, secrete IL-4, IL-5, IL-9, and IL-13, and are involved in protection against parasitic infections and in allergic disorders [1,2].