DMPK and myotonic dystrophy type 1: Administration of this ASO in muscle tissue of DM500 mice (a DM1 model carrying > 300 DMPK CTG repeats) and HSALR20b mice (a DM1 model expressing human skeletal actin transcripts containing ∼250 DMPK CTG repeats) silenced the expression of mutant RNA and decreased the formation of nuclear foci in a selective and (CUG)n-length-dependent manner (Mulders et al., 2009).