Through analysis of the clonal involvement in distinct hematopoietic stem and progenitor cell compartments, as well as mature blood cell lineages, preleukemic clones containing the DNMT3A mutation but not the other driver mutations detected in the AML cells have been tracked to the HSC compartment [31, 32], and unlike the transformed AML cells, these preleukemic cells contribute to both myeloid and lymphoid lineages [31], again suggesting preserved hematopoietic functions prior to acquisition of transforming events. The gene discussed is DNMT3A; the disease is acute myeloid leukemia.