SFRP1 and cancer: We have analyzed the methylation frequency of multiple tumor suppressors (APC, DAPK, E-cadherin, hMLH1, IRF8, p14, p15, RASSF1A, SFRP1 and SOCS-1) that are found to be frequently methylated in various human cancer including bladder cancer [11,20-25] in primary bladder UC tissues from Taiwan (104 cases), Hong Kong (82 cases) and China (Beijing, 24 cases) by methylation-specific PCR (Figure 1A).