IGF1 and sarcopenia: Of note, PGC1α4 could be served as a rational target to improve sarcopenia since it has been shown to prevent or treat muscle wasting during muscle injury or cancer related cachexia by engaging multiple beneficial mechanisms for muscle hypertrophy, that is, IGF1 induction, myostatin inhibition, and increased protein synthesis via mTOR (Ruas et al., 2012; White et al., 2014).