A CpG in the promoter of the Wnt inhibitory factor-1 (Wif1) gene, a gene silenced by hypermethylation in bladder tumors and other cancers [16,17], was methylated 54% of the time in egg-injected mice, 34% in nitrosamine-fed mice, and 7% in control mice. This evidence concerns the gene WIF1 and urinary bladder neoplasm.