Previously, we showed that the activity of the miR-509-3p miRNA, one of miRNAs involved in the posttranscriptional regulation of CFTR gene of CF and CF-RD, could be inhibited through the use of the 14-mer PNA1 fully complementary to the first fourteen bases of miR-509-3p [37]. This evidence concerns the gene CFTR and cystic fibrosis.