Hence, although type-2 cytokine- and antibody-mediated resistance to GI nematode infections typically rises with age in human and wildlife populations, it is conceivable that IFN-γ availability related to host age, genetic background and the infection history with other pathogens impacts this process in natural systems in similar ways as reported here for primary nematode infection under highly controlled environmental conditions. This evidence concerns the gene IFNG and Nematoda infectious disease.