Can exercise increase natural killer cell infiltration of the prostate?

Regular exercise is a well-established intervention to reduce prostate cancer treatment toxicities [1]. In addition, higher levels of physical activity are associated with longer prostate cancer survival [2]. However, the mechanisms underlying the protective effect of exercise against tumour development/ progression remain to be clearly elucidated. In this context, Djurhuus et al. [3] have reported on the first human study examining the effects of an exercise intervention on natural killer (NK) cell infiltration in localised prostate cancer. This is an important question: NK cells are constantly on high alert for malignant cell transformation, monitoring target cells for surface expression of NK cell-activating receptors, and are