Specifically, in the absence of infection, CD4+ and CD8+ T cells maintain close to one million cells/MLN in WT and CD118−/−[18] whereas following 100 PFU/cornea HSV-1, similar levels (2-3 million) of CD4+ and CD8+ T cells were isolated from the MLN of WT and CD118−/− mice 6 d PI. Here, CD4 is linked to infection.