TGFB1 and cystic fibrosis-related liver disease: To determine the association between non-CFTR genetic polymorphisms and CFLD, Bartlett et al. in a two-stage case-control study enrolling patients with CF and severe liver disease with portal hypertension examined 9 functional variants in 5 genes previously studied in CFLD, including α1-antitrypsin (SERPINA1), angiotensin-converting enzyme (ACE), glutathione S-transferase (GSTP1), mannose-binding lectin 2 (MBL2), and transforming growth factor β1 (TGFB1).