Other studies have demonstrated that HIF is required for barrier protection (Kelly et al., 2015) and that administration of dimethyloxalylglycine (DMOG), a proline hydroxylase inhibitor, to stabilize HIF exerts a significant protective effect against DSS-induced colitis by preventing tumor necrosis factor-α (TNF-α; also known as TNF)-induced epithelial apoptosis (Cummins et al., 2008; Hindryckx et al., 2010). Here, TNF is linked to colitis.