CXCL13 and tick-borne encephalitis: Several studies have reported a host of cytokines to be upregulated in the blood of TBE patients including Chemokine (C-C-motif) Ligand (CCL)5, CCL7, Chemokine (C-X-C-motif) Ligand (CXCL)10, CXCL11, CXCL13, Tumor Necrosis Factor (TNF)-α, Interferon (IFN)-γ, Interleukin (IL)-1 α, IL-6, IL-15, and IL-18, among others (47–53), though a “TBE-specific” cytokine profile, which could be useful for diagnostic purposes, has not been defined.