MSTN and cancer: Acting through the same receptor than MSTN (ActRIIB), Activin A is also found to be increased in cancer cachexia (Leto et al., 2006; Loumaye et al., 2015; Matsuyama et al., 2015; Chen J. L. et al., 2016; Chen M. C. et al., 2016; Barreto et al., 2017; Zhong et al., 2019; Bernardo et al., 2020) and an independent prognosis factor of survival in cancer patients (Loumaye et al., 2017).