In a TBEV-infected mouse model, CD8+ T cells was also shown to play a pivotal role in the immunopathology of TBE as evidenced by prolonged survival of severe combined immunodeficiency (SCID) or CD8−/− mice following infection, compared with immunocompetent mice or mice with adoptively transferred CD8+ T cells [9]. The gene discussed is CD8A; the disease is immunodeficiency disease.