EPO and anemia: In line with this observation, we hypothesize that treatment with HIF-hydroxylase inhibitors (i.e., HIF agonist) is potentially beneficial for IBD patients by exerting a dual effect: 1) suppression of mucosal inflammation, as demonstrated in in vivo studies (Cummins et al., 2008; Robinson et al., 2008; Tambuwala et al., 2015; Colgan et al., 2020), and 2) ameliorate iron deficiency and anemia by stimulating intestinal iron absorption in the non-inflamed mucosa (our study), in combination with systemic endocrine effects (e.g., upregulation of erythropoietin) (Figure 7).