For instance, a protein TCL1 that is overexpressed in a number of human T-cell malignancies, including mature leukemias, T-cell prolymphocytic leukemia, and B-cell malignancies, such as Burkitt’s lymphoma and CLL (28, 29), binds to Dnmt3a and Dnmt3b and inhibits their activities (30) raising a possibility that Dnm3b activity is functionally decreased in a large number of hematologic malignancies. Here, DNMT3A is linked to B-cell chronic lymphocytic leukemia.