In contrast, six of the ten small molecules activein the NanoBRETassay, A2, A4, A6, B1, B2, and B3, rescued MBNL1 exon 5 alternativesplicing when DM1 myotubes were treated with 50 μM compoundwithout affecting MBNL1 protein expression levels (Figure B and Figure S23A,B). This evidence concerns the gene MBNL1 and myotonic dystrophy type 1.