CCR5 and tick-borne encephalitis: The CCR5 expression in the peripheral blood was lower in CCR5Δ32 carriers than in wt/wt homozygotes both in the terms of the fraction of CCR5-positive cells and CCR5 MFI, but the expression levels associated with both genotypes overlapped, especially in TBE patients in examinations II and III (Fig. 5b).