CD8A and cancer: Whilst it was noted that NK cells elicited much of the killing, it should be noted that CD8+ T cells likely contributed to cancer cell killing in this study (161), as CD8+ T cells are also profoundly mobilised by acute exercise (157) and because assays were performed with peripheral blood mononuclear cells containing T cells – which display cross-reactivity against non-self human leukocyte antigen (HLA) (162).