Genetic diseases such as Cystic Fibrosis are caused by alterations (mutations) in the sequence of “letters” (nucleotides) that make up the DNA (genome) of the cells. The genome contains the information (genes) whose translation into structural and functional elements (proteins) requires an intermediary (messenger RNA – mRNA) that reflects the gene sequence and whose ‘letters’ (ribonucleotides) are read by the ribosomes as triplets (codons ). The non-sense (stop) mutations of DNA are due to the substitution of a single nucleotide in a codon of sense (coding), and then in messenger RNA, and cause the production of altered proteins. To correct these mutations and obtain the synthesis of the integrated CFTR protein, the project involves the use of a new approach to correction (editing) of the messenger RNA (REPAIR = RNA Editing for Programmable A to I Replacement) developed in the laboratory of the Dr. Feng Zhang (Broad Institute, USA). The REPAIR system (via the CRISPR-dCas13b / ADAR2 complex) as the proofreader identifies and modifies the wrong single ‘letter’ (ribonucleotide) of the text (triplet) thus allowing the correct synthesis of the protein. REPAIR can correct the stop mutations on the messenger RNA by directing, through the dAS13b protein, the protein ADAR2 on the nucleotide molecule Adenosine (A) of the stop nucleotide triplet (UGA), which is modified in Inosin, ribonucleotide recognized as guanosine (G) from ribosome (the UGA codon becomes UGG). RNA editing is a new and potential method for the genetic correction of the basic defect of Cystic Fibrosis which transforms the nonsense triplet (stop) into one of sense (coding); it also has the advantage of being transitory and of reducing the possible risks of permanent changes in the genome.