TNFRSF18 and infection: We also examined the role of GITR with the acutely infecting Armstrong variant of LCMV and observed approximately two- to three-fold more GP33–41-specific CD8 T cells in GITR+/+ compared to GITR-/- at day eight p.i. (p<0.01 in two of the three experiments, total of ten mice per group), however both GITR+/+ and GITR-/- mice cleared LCMV Armstrong infection by day eight p.i.