MBNL1 preferentially recognizes CUG or CCUG repeats when they are pathologically expanded [9], [10] and is sequestered by ribonuclear foci in DM1 and DM2 cells [9], [11], [12] resulting in a loss of MBNL1 activity. The gene discussed is MBNL1; the disease is myotonic dystrophy type 1.