SLC6A14 has been also proposed (Ruffin et al., 2020) to modify the phenotype of cystic fibrosis (CF) – a fatal genetic disorder caused by mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene (Riordan et al., 1989; Rommens et al., 1989). Here, CFTR is linked to cystic fibrosis.