RANKL/OPG ratio, a preferable harmful determinant of bone mass, increase with age (Chung et al., 2014; Zhang et al., 2016; Piemontese et al., 2017). IL-3 can improve the RANKL/OPG ratio and act as a potent medicine to treat osteoporosis (Singh et al., 2018). RANKL inhibitor Dmab can rescue muscle function in postmenopausal women, and also in osteo-sarcopenic Pparb–/– mice (Bonnet et al., 2019). The gene discussed is PPARD; the disease is osteoporosis.