Laboratory confirmation criteria include: the presence of TBE-specific IgM and IgG antibodies in serum, and/or the presence of TBE-specific IgM or IgM and IgG antibodies in cerebrospinal fluid (CSF), and/or seroconversion or a significant increase in TBE-specific antibodies titer in two serum samples, and/or the detection of TBE viral nucleic acid in CSF, blood, or other body fluid or tissue, and/or isolation of the TBEV from specimen [14,15]. Here, CD40LG is linked to tick-borne encephalitis.