CLOCK and colitis: This contrasts with recent findings by Niu et al., who reported colitis-promoting effects in mice with a genetic, epithelium-specific clock deficiency (Bmal-1IEC−/−), using either DSS-induced mice or genetically susceptible (Bmal-1IEC−/−xIL-10−/−) double knockout mice.12 These different observations could indicate stronger and broader disruptive effects of the Bmal1-dependent genetic clock deficiency on the intestinal inflammatory and metabolic milieu compared to those induced by altered light/dark cycles.