Next, we adoptively transferred small numbers of SMARTA CD4+ T cells from these three genotypes into separate CD90.2 C57BL/6 wild type mice (day -1) and infected them with 200 plaque forming units (pfu) LCMV WE (day 0), which results in an acute infection (Figure 2A) that we analysed on day 8. This evidence concerns the gene CD4 and infection.