In this acute challenge model, GFI1hi CD8+ T cells expanded approximately fourfold more than GFI1lo CD8+ T cells by day 7 post LCMVArm infection (Fig. 2f,g and Extended Data Fig. 3d), demonstrating the enhanced proliferative potential of GFI1hi CD8+ T cells in response to a secondary infection. Here, CD8A is linked to infection.