Pu.1 function may be deregulated in AML by mutation (7% in some studies, although not observed in the recent TCGA report) or by a SNP in an upstream enhancer (perhaps in 65% of humans) as well as by other fusion genes and down-regulation in mice can lead to leukemia and lymphomas[52,53]. This evidence concerns the gene SPI1 and acute myeloid leukemia.