DKK3 and acute lymphoblastic leukemia: The reduced expression of DKK3 has become a hallmark of several haematologic malignancies, such as ALL, CLL, AML and myelodysplastic syndrome, and its down‐regulation is associated with a poor prognosis in patients.11, 32, 33, 34DKK3 promoter hypermethylation is associated with DKK3 silencing in ALL cells, and DKK3 expression was restored after exposure to 5‐AdC, which indicates that hypermethylation is one of the mechanisms by which DKK3 is silenced in ALL cells.11, 23 These previous results are consistent with our current work.