It has been suggested that several members of the TGFβ superfamily, including activin A, can affect skeletal muscle by limiting the differentiation of myoblasts.7, 8 Moreover, the transcription factors SMAD2 and SMAD3, which are activated by, for instance, activin A, can induce atrophy in adult myofibers, in a mechanism involving the AKT/mammalian target of rapamycin pathway.9 Although convincing data underscores a role of activin A in cachexia development, other signalling substances and pathways are likely also involved. The gene discussed is SMAD3; the disease is Cachexia.