MTOR and cancer: By acting on the well-documented anabolic mTOR axis, myokines released during muscle contraction slow proliferation, induce apoptosis, and suppress protein synthesis in MCF7 cancer cells, both in vitro and in vivo, to the extent that exercise-conditioned perfusate treatment in mice with xenografted tumors completely abrogates tumor growth at three- and 4-weeks post-implantation.