CFTR and cystic fibrosis: Moreover, two independent phase-2 clinical trials demonstrated that CF patients bearing the CFTR-F508 mutation responded to a combination of cysteamine plus EGCG by an improvement of CFTR function (as determined by the sweat test and by measuring plasma membrane expression and function of the mutated CFTR protein in respiratory epithelia), as well as by a reduction of lung inflammation (as indicated by a decline in inflammatory cytokines in the sputum)25,65.