Another study demonstrated higher promoter CpG hypermethylation and lower expression of mRNA transcripts for sFRP-1, sFRP-2, sFRP-4, and sFRP-5, Dkk-3, and Wif-1 genes in bladder tumor compared with normal bladder mucosa showing an inverse correlation. This evidence concerns the gene SFRP2 and urinary bladder neoplasm.