In Plac1‐CKO mice, proliferating cells were restricted mainly to the basal layer of the epithelium, whereas proliferating cells were widely distributed in dysplasia and tumor lesions in Plac1‐WT mice, which presented a greater cell proliferation ratio than Plac1‐CKO mice (Figure 3J,K, p = 0.0011). This evidence concerns the gene PLAC1 and neoplasm.