Feeding a small amount of bile acids with minimal enteral feeding is a frequent clinical practice in PN-fed infants to treat cholestasis with mixed results (44, 45), yet the most common bile acid used is ursodeoxycholic acid, which is not an NR1H4 agonist and has been shown to exert NR1H4 antagonistic effects (46). Here, NR1H4 is linked to cholestasis.