With LUM/IVA therapy, ICM in these young patients demonstrated functional rescue of F508del-CFTR in the intestinal epithelium at a level of approximately 30% of normal CFTR function, which is comparable to the CFTR activity previously observed in pancreas sufficient patients with CF who have a spectrum of CFTR variants with residual function (Hirtz et al., 2004; Stanke et al., 2008). Here, CFTR is linked to cystic fibrosis.