SFRP4 and acute myeloid leukemia: The frequencies of hypermethylation of Wnt inhibitors (in descending order) were as follows: 31.6% for SFRP1, 30.1% for DKK1, 26.0% for Wif-1, 19.3% for SFRP2, 12.6% for SFRP5, and 1.5% for SFRP4. Taken together, 166 AML patients (61.7%) had promoter hypermethylation of at least one Wnt inhibitor at diagnosis.