Genes involved in skeletal muscle development and function, including Bin1, Clcn1, Ldb3, Serca1, and Tnnt3, are aberrantly spliced in Mbnl1-knockout mice as well as in DM1 patients, in which MBNL1 is sequestrated to the nuclear RNA foci with abnormally expanded CUG-repeats43–45. Here, MBNL1 is linked to myotonic dystrophy type 1.