Based on these and other studies, we examined possible relationships between single nucleotide polymorphisms in the IL-4 (−590 C/T), IL-13[(−1055 C/T), (−591A/G), (R130Q G/A)], IL-10 (−1082 A/G; −819 C/T; −592 C/A), and IFN-γ (+874A/T) genes or promoters in relation to resistance and susceptibility to schistosomiasis of a cohort of occupationally exposed adult men many of whom we have studied longitudinally for as long as 12 years [40],[41]. This evidence concerns the gene IFNG and schistosomiasis.