In our group of TBEV-infected patients, an activated Th lymphocyte population in csf was enriched in CCR5-expressing cells, suggesting that either they were preferentially attracted into csf or that, alternatively, CCR5 was up-regulated on activated Th lymphocytes in the pro-inflammatory csf environment, possibly influencing their further trafficking, as suggested by Giunti et al. for neuroborreliosis [26]. The gene discussed is CCR5; the disease is Lyme disease.