We then co-transferred equal numbers of naïve WT (CD45.1+CD45.2−) and OX40−/− (CD45.1+CD45.2+) cells into C57BL/6 (CD45.1−CD45.2+) recipients prior to LCMV cl13 infection or LCMV Armstrong infection. This evidence concerns the gene TNFRSF4 and infection.