HIF1A and inflammatory bowel disease: Moreover, Sun and colleagues showed that IEC-derived HIF-1 contributes to the maintenance of mucosal homeostasis by inducing interleukin (IL-33) expression in IBD [56], and later the same group showed that IECs-derived HIF-1 is essential for the homeostasis of intestinal intraepithelial lymphocytes and intestinal microbiota [57].