HNF4A and inflammatory bowel disease: Within the intestinal epithelium, NRs such as VDR, HNF4α, LXR, PPARγ, LRH1, and NR2F6 play protective roles in intestinal epithelial integrity (Figures 1, 2); decreased mRNAs have also been validated in intestinal samples from IBD patients (10, 12) (Table 1).