Thus, the S/MAR-based pEPito plasmid designed for episomal persistence has been demonstrated to be efficient in in vitro and in vivo studies15, while recently, S/MAR-stabilized plasmids encoding the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene, were added to the tools used in the long standing quest for Cystic Fibrosis gene correction16. The gene discussed is CFTR; the disease is cystic fibrosis.