Pharmacological inhibition of MPO by synthetic inhibitor AZD3241 has shown to improve experimental colitis symptoms and activate the heme oxygenase-1 (HO-1)/nuclear factor erythroid factor 2-related factor 2 (Nrf2) signalling pathways [33], whilst the inhibition of PAD4 by the pan-PAD inhibitor Cl-Amidine ameliorated experimental colitis and up-regulated glutathione peroxidase 1 (GPx1) and superoxide dismutase 1 (SOD1) expression [34,35]. Here, HMOX1 is linked to colitis.