NEUROG3 and chronic diarrheal disease: In addition, human enteroendocrine cell deficiency as well as mutations in enteroendocrine gene NEUROG3 have been linked to chronic diarrhea and malabsorption, and recently, intestinal enteroendocrine cells have been suggested to play a role in mediating intestinal immune tolerance (Ohsie et al., 2009; Sifuentes-Dominguez et al., 2019; Wang et al., 2006).