For example enhanced IFNγ in Il17a-KO mice has been described in a viral infection,28 experimental visceral leishmaniasis, and Toxoplasma gondii infection.29 Evidence also exists in the context of helminth infection, where a lack of IL-17A drives elevated IFNγ during infection with the filarial nematode Litomosoides sigmondontis30 or Schistosoma japonicum31 and Schistosoma mansoni. This evidence concerns the gene IL17A and helminthiasis.