TET1 and neoplasm: In the meantime, the reduced methylation status of DACT2, Wnt5A, and SFRP2 promoter was detected in TET1-CD-expressing tumor cells, with increased unmethylated sites at the promoter CpG regions (Fig. 8c), suggesting that TET1 really acts as a demethylase to renew expression of multiple TSGs in tumor cells.