With respect to testing miRNA therapeutics products in animal models prior to clinical trials, we would like to underline that, at least in theory, ago-miRNA and anti-miRNA products targeting genes relevant to CF (for instance the human CFTR and IL-8 genes, as discussed in Section 4 and Section 5) can be assayed in animal models, obtaining informative results, since the sequences of both regulatory miRNAs and those of miRNA-binding sites are conserved throughout the molecular evolution [93,106,111]. This evidence concerns the gene CXCL8 and cystic fibrosis.