The most frequent mutation, p. Phe508del, F508del thereafter, is carried at least on one allele by around 80% of people with CF (pwCF) worldwide and results in defective CFTR protein trafficking due to protein misfolding, reduced stability at the cell surface, and dysfunctional channel gating (Pranke et al., 2019). The gene discussed is CFTR; the disease is cystic fibrosis.