The efficacy of novel small molecules derivatives of the PTC124 previously identified will be evaluated in CF cells (primary human bronchial epithelial cells with G542X mutation and in immortalized epithelial cells of cystic fibrosis patients). Moreover new molecules will be selected by a virtual screening based on “in house” and available public compound libraries; then lead compounds will be designed and synthesized. The mechanism of action of PTC’s read-through promoters will be investigated: molecular dynamics and docking studies aimed to model the interaction between the bioactive synthesized compounds and their possible cellular target will be carried out.