IL17A and tick-borne encephalitis: Studies on cytokine biology in TBE showed increased serum levels of IL-1α, TNF-α, IL-6, IL-8, IL-12, IL-15, IL-18 and IFN-γ, as well as increased concentrations of IL-1β, IL-16, Th17 cytokines (IL-17A, IL-17F) and Th22 cytokine IL-22 in the CSF of TBE patients in comparison with controls [15,16,19,20].