Consistent with this, anti–PD-L1 and anti–CTLA-4 administration to block T cell exhaustion (Fig. 7F–H) led to an increase in T-bet expression within the overall CD4+ T cell population (Fig. 7I) and corresponded with a significant increase in the level of cellular glycolysis and oxidative phosphorylation by CD4+ T cells on day 15 of infection (Fig. 7J). Here, CD4 is linked to infection.