The project intends to improve the positive effects of CFTR modulators, by increasing CFTR protein synthesis and thus providing abundant substrate to correctors and potentiators for the greatest possible protein’s recovery and normal CFTR function. The candidate molecules are peptide nucleic acids (PNA); they will be tested in primary respiratory cells from CF patients, carrying residual function mutations (RF). The PNA can both inhibit and amplify the transcription of the genetic code from gene DNA to messenger RNA, which is the mediator for the synthesis of the CFTR protein. Several PNAs will be produced and tested, selecting those with greater amplification activity, suitable as drug candidates, which could be further tested in humans in association with the available CFTR modulators.