While it is clear that MBNL1 is depleted from nucleoplasm through recruitment into ribonuclear inclusions both in DM1 and DM2 even when clinical symptoms and muscle alterations are very mild [35], [62]–[65], CUGBP1 overexpression has been clearly demonstrated in DM1 but not in DM2 muscle biopsies. Here, CELF1 is linked to myotonic dystrophy type 1.