Mitochondrial metabolism is crucial for lasting CD8 T cell control of viral infections: while effector T cells upregulate glycolysis to rapidly generate ATP, memory T cells use mitochondrial oxidative phosphorylation to support their long-term persistence (Cham and Gajewski, 2005; Jacobs et al., 2008; van der Windt et al., 2012; van der Windt et al., 2013; Chang et al., 2013). Here, CD8A is linked to viral infectious disease.