CXCR5 and viral infectious disease: He et al. showed that in the context of chronic viral infection, approximately one-third of virus-specific effector CD8+ T cells expressed CXCR5, with these cells exhibiting higher costimulatory molecule expression but fewer coinhibitory molecules (including PD1) than CXCR5-CD8+ T cells, suggesting that CXCR5 expression is associated with less exhausted states.