The first evidence that a WT1 mutation could be leukemogenic was a report describing a Wilms tumor survivor with WAGR syndrome, who by definition harbored a germline heterozygous deletion of the WT1 gene, and later developed acute myeloid leukemia (AML) with a new somatic WT1 mutation in the remaining allele [8]. This evidence concerns the gene WT1 and acute myeloid leukemia.