In vitro studies on human BBB models revealed that HBMEC, used as a substitute for endothelial cells of the BBB, expresses CXCR4 and CCR5, co-receptors involved in HIV infection of target cells, and gp120 can trigger a reduction in an array of TJ proteins (ZO-1, ZO-2, and occludin) expressed by an HBMEC monolayer (in vitro study) [173]. This evidence concerns the gene OCLN and HIV infectious disease.