Under healthy conditions the endothelial cells of the BBB express very low levels of CAMs, however the expression of multiple CAMs including ICAM-1, VCAM-1, and selectins upon inflammatory stimulation multiple sclerosis (MS) [12] or infection with viruses such as human immunodeficiency virus (HIV) [13], [14] and herpes simplex virus [15]. Here, ICAM1 is linked to infection.