Different editing strategies have been used to contrast the toxic effect of the mutant DMPK transcript in DM1: (i) blocking transcription using deactivated Cas9 (dCas9) along with sgRNAs targeting CTG repeats [124]; (ii) degradation of single-stranded CUG-repeat RNA using RNA-targeting Cas9 (RCas9) [177]; (iii) insertion of a premature polyA signal in the DMPK gene [178]. This evidence concerns the gene DMPK and myotonic dystrophy type 1.