CD8A and cancer: For instance, CD4+ T cells may become prone to depletion (Heinrich et al., 2021), while CD8+ T cells may lose their mitochondrial wellness (Wabitsch et al., 2022) and as of that, they can impede the effectiveness of anti-cancer treatments that depend on them (e.g., anti-PD-1 therapies that are based on CD8+ T cell responses).