No correlation was observed between the frequency of CD4+ T-cells and the nPVL (data not shown), but nPVL positively correlated with the frequency of CD4+ T-cells proliferating in the spleen after 60 days of infection (Linear regression, R2 = 0.952, p = 0.001) as shown by Ki67 staining (Figure 1B). This evidence concerns the gene CD4 and infection.