Accumulating evidence suggests that elevated levels of MSTN and its analog activin A lead to the progression of atrophy and cachexia.474 ActRIIB, a high-affinity activin type 2 receptor, plays a crucial role in mediating signaling pathways activated by a particular group of TGF-β family ligands, including MSTN, activin, and GDF11. This evidence concerns the gene MSTN and Atrophy.