IL17A and Allergy: In the traditional view, we have three basic lines: type 1 immunity against intracellular pathogens (TH1-defence, viruses and intracellular bacteria, production of IFNγ-cytokine, inflammation/autoimmunity); type 2 immunity against multicellular parasites (TH2-defence, production of IL4 and IL5 cytokines, allergy/asthma); and type 3 immunity against extracellular pathogens (TH17-defence, bacteria and fungi, production of IL22 and IL17 cytokines, inflammation/autoimmunity), (Annunziato et al., 2015).