#$%^&*AU2020202406A120200430.pdf#####ACTRIIB PROTEINS AND VARIANTS AND USES THEREFORE RELATING TO UTROPHIN INDUCTION FOR MUSCULAR DYSTROPHY THERAPY 5 ABSTRACT In certain aspects, the present invention provides compositions and methods for inducing utrophin expression in muscle with an ActRIIB protein as therapy for muscular dystrophy. The present invention also provides methods of screening compounds that 0 modulate activity of an ActRIIB protein and/or an ActRIIB ligand. 60