Assays were performed in HEK293 cells for A) F508del-CFTR For the F508del-CFTR measurements since this mutant does not respond well to Fsk alone (Fsk + VX-770 potentiator is required to obtain a detectable signal) we compared the CFTR inh172 (inhibitor) response (F1/'F-CFTRinh172'; where F1 represents peak RFU immediately before inhibitor addition and 'F-CFTRinh172' is the minimum RFU reached at the end of the CFTR inh172 measurement cycle). For each of F508del-CFTR data for three proteins not detected as interactors (first three bars following CFTR only) are shown as negative controls. Fluorescence signals were normalized to the CFTR-only control and the statistical significance of differences assed by unpaired t-test (*p<0.05, **p<0.01 and ***p<0.001). Samples run in n=3 replicates, and all values are mean ± s.d. 