In certain aspects, the present disclosure provides compositions and methods for inhibiting activity of TGFβ superfamily ligands, particularly ligands such as GDF8, GDF11, activin A, activin B, activin C and activin E, in vertebrates, including rodents and primates, and particularly in humans. In some embodiments, the compositions of the disclosure may be used to treat or prevent diseases or disorders that are associated with abnormal activity of a follistatin-related polypeptide and/or a follistatin ligand.
