We first selected heterozygous and homozygous Dmpk-(CTG)480 KI mouse models, as they reproduce characteristic DM1 pathological molecular signatures, including MBNL sequestration on Dmpk-(CUG)480 RNAs, RNA mis-splicing in vulnerable cell types and DMPK protein loss68,69. Here, MBNL1 is linked to myotonic dystrophy type 1.