MKI67 and infection: Although both wild-type and HD CD8+ T-cells numbers were similarly increased 15 days post infection (S1 Fig), using the cell-cycle progression marker Ki67, we observed a statistically significant interaction of T. gondii and HD on CD8+ T-cell proliferation in both spleen (F(2,12) = 28.84, p = 0.0002) and brain (F(2,12) = 22.88, p = 0.0004).