Figure 2.

Evaluation of CFTR channel function. Channel activity is expressed as the initial fluorescence quenching rate (QR) of the yellow fluorescent protein (YFP) protein by the iodide influx in Fischer rat thyroid (FRT) cells permanently co-transfected with the WT-CFTR (a) and the F508del-CFTR (b). Cells were treated with DMSO, 5 µM VX809, 5 µM VX661, 10 µM corr4a and 5 µM VX325. Data are expressed as mean ± standard error of the mean (SEM). For each condition, the number of measurements (n) is indicated inside the bars of the graphs. Asterisks indicate a significant difference (* p < 0.05) with respect to the control, DMSO-treated samples.