Expression of the F508del-CFTR N-half co-expressed with the C-half. (A) Detection of M1N1-F508del (a) and M2N2 (b) in whole cell lysates of untransfected (untransf.) and transiently co-transfected HEK-t cells treated with DMSO (control), VX809, VX661, corr4a and VX325. (c) Expression of the protein actin in the same samples in (a) and in (b). The molecular weights of the proteins of the molecular weight marker that was run in the SDS-PAGE are shown on the left of each blot. (d) Normalized expression of the F508del-M1N1 polypeptide. (e) Bar graph indicating the quantification of the total M2N2 protein expression, calculated as the sum of bands B and C, normalized by the actin expression. (f) Bar graph indicating the quantification of the mature, fully glycosylated fraction of the M2N2 protein, expressed as the C/(C + B) band ratio. Data are expressed as mean ± standard error of the mean (SEM) of at least four independent experiments. Asterisks indicate a statistical significance versus the control: * p < 0.05.