However, when considering the downregulation of CXCL12 as a therapeutic strategy, it is worth noting that recent studies evaluating T cell responses to viral infection in vitro have found that CXCL12 at the BBB endothelium can promote CD8+ migration across the BCSF interface, suggestive of a location-dependent role [133]. Here, CXCL12 is linked to viral infectious disease.