Moreover, the Pparb/d-null mice used for these studies also revealed no difference in colon tumorigenesis in previous studies using either the APCmin/+ mouse line or the AOM-induced colon cancer model, and the latter model utilized an identical intestinal-specific PPARβ/δ disruption approach.54,55 Although this latter disparity could be reflected by strain differences, the lack of reproducibility with related models raises concerns about this study. This evidence concerns the gene PPARD and colonic neoplasm.