Most interestingly, dietary supplemental sulindac was able to inhibit tumor formation in the Apc+/−/p21+/+ mice, but not in the mice in which even a single p21 allele was inactivated (i.e. Apc+/−/p21+/−) [3], because the remaining wild-type p21 allele is inactivated by hypermethylation of a CpG cluster in its promoter in both the intestinal mucosa as well as in the tumors that form [8]. Here, APC is linked to neoplasm.