A full-length human utrophin transgene expressed from a skeletal muscle-restricted promoter/enhancer (Tg(ACTA1-Utrn)2Ked; “Fiona”) was used to rescue the skeletal muscle pathology of dystrophin/utrophin-deficient mice (utrn–/– mdx; dko), allowing progression of cardiomyopathy (Fiona/dko) (24, 25). Here, UTRN is linked to cardiomyopathy.