CD8A and infection: When equal numbers of WT (CD45.1+) and GFI1ΔCD8 (CD45.1+CD45.2+) P14 CD8+ T cells were co-transferred into congenic recipients, both WT and GFI1ΔCD8 P14 CD8+ T cells expanded equivalently by day 5 after LCMVc13 infection (Extended Data Fig. 5a).