Previous evidence of the anti-inflammatory role of the NRG-4/ErbB4 axis came from studies on inflammatory bowel diseases, such as Crohn’s disease and ulcerative colitis (Frey et al., 2009; Bernard et al., 2012; McElroy et al., 2014; Schumacher et al., 2017). Here, NRG4 is linked to inflammatory bowel disease.