CELF1 and myotonic dystrophy type 1: CUG-BP1 and ETR-3 like factor (CELF) member CUG-BP1 does not bind ds(CUG) hairpins nor co-localizes with ribonuclear foci but its activity is increased in DM1 myoblasts, skeletal muscle, and heart tissues [36, 66, 67] (see [68] for a review about CELF RNA binding proteins).