This is mainly due to the fact that schistosomiasis is dominated by the Th1 immune response at 6–8 weeks and then reaches a peak (Rabello, 1995), and subsequently, a large number of pro-inflammatory cytokines such as tumor necrosis factor, interleukin-1, and interleukin-6 appear (de Jesus et al., 2002). Here, TNF is linked to schistosomiasis.