In certain aspects, the disclosure provides multispecific binders (e.g., ActRIIB:TβRII heteromultimers comprising an ActRIIB polypeptide and a TβRII polypeptide). In some embodiments, the disclosure provides for novel binders comprising a TβRII polypeptide and a heterologous portion. The disclosure further provides that such multispecific binders (e.g., ActRIIB:TβRII heteromultimer) may be used to treat various disorders or conditions.