Whether the spleen is a significant source of CD11b+Ly-6Chi monocytes during CNS inflammation caused by neurotropic viruses such as JEV and WNV is yet to be determined, but both spleen and BM are considered to be critical for supplying CD11b+Ly-6Chi monocytes to the inflamed CNS, particularly in cases of acute and severe infection, in which large numbers of these cells are rapidly deployed and recruited to the brain42. This evidence concerns the gene ITGAM and infection.