Our previous study has shown that JMJD2D-/- mice are more sensitive to dextran sulfate sodium-induced colitis (DSS) due to the defect in the colonic regeneration, which is characterized by an increased in colonic epithelial cells apoptosis and a decrease in colonic epithelial cell proliferation via impaired Hedgehog signaling activation [17], indicating that JMJD2D plays an important protective role in DSS-induced colitis. The gene discussed is KDM4D; the disease is colitis.