TNFSF11 and cancer: For example, skeletal muscle secretes MSTN to induce RANKL-mediated osteoclast formation in vitro through Smad2-dependent regulation of the nuclear factor of activated T cells.147 The exercise-induced muscle factor β-aminoisobutyric acid prevents bone loss and muscle dysfunction by counteracting ROS-mediated mitochondrial breakdown and osteocyte apoptosis.148 The regulation of muscle‒bone interactions in cancer cachexia remains elusive, and new investigations should be pursued to reveal the complex mechanisms involved.