Transposon-mediated insertional mutagenesis was then performed to identify cooperating B-ALL driver genes and led to the identification of five transposon common insertion sites, including one in the Zfp423 gene, which was associated with a significant increase in the occurrence of B-cell precursor ALLs in these mice [102]. This evidence concerns the gene ZNF423 and precursor B-cell acute lymphoblastic leukemia.