MSTN and cancer: Several authors conducted experiments with inhibition of the MSTN/Activin A pathway and found a reduction, or even a complete reversal, in the decrease of muscle mass and function in pre-clinical models (Liu et al., 2008; Benny Klimek et al., 2010; Murphy et al., 2011; Busquets et al., 2012a, b; Gallot et al., 2014; Hatakeyama et al., 2016; Levolger et al., 2019; Ojima et al., 2020; Pettersen et al., 2020), leading to the consideration of this pharmacological strategy for human cancer patients.