Since the discovery that the cell surface expression defects of F508del-CFTR and other processing mutants could be partially rescued in vitro by incubating cells that the express mutant CFTR at a low temperature (27 °C) [11], in the presence of nonspecific osmolytes such as glycerol [1,15,16], or with organic solutes such as myoinositol [17], research in CF has been oriented towards the development of a drug-mediated rescue approach. The gene discussed is CFTR; the disease is cystic fibrosis.