Moreover, infection of primary human cortical astrocytes by tick-borne encephalitis virus results in a persistent, productive infection that is associated with astrocyte activation and upregulation of several proinflammatory cytokines/chemokines including IFN-γ, TNF-α, IL-1β, IL-6, IL-8, IFN-γ-induced protein 10, MIP, and RANTES [27, 28]. This evidence concerns the gene IL6 and infection.