CD8A and neoplasm: Studies in rodents have shown that exercise can directly reduce tumour growth through mobilisation, activation, and increased tumour infiltration of natural killer (NK) and CD8+ T-cells in an epinephrine-dependent manner (Pedersen et al., 2016; Kurz et al., 2022; Gomes-Santos et al., 2021; Rundqvist et al., 2020).