Interestingly, in our pilot experiments, we have found a tendency for a higher proportion of CD3+CD8+ versus CD3+CD4+ lymphocytes in csf lymphoid cell population in patients with the more severe manifestation of TBE, which is consistent with the hypothesis that cytotoxic T cells are involved in TBE-related immunopathology while Th cells we chose for the study are protective [13, 18]. Here, CD4 is linked to tick-borne encephalitis.