To assess whether the EPAC1-mediated CFTR stabilization also occurs in intestinal organoids (and thus whether this model can be used to study the EPAC1 pathway in materials derived from individuals with CF), we used the FIS assay, considering that levels of CFTR function detected are dependent not only on the gating of the channel but also on the amount of protein at the PM. This evidence concerns the gene RAPGEF3 and cystic fibrosis.