To investigate if WNK1 is required for AML progression in vivo, we generated AML cell lines harbouring an MLL-AF9 translocation by transducing c-KIT-enriched bone marrow cells from mice with a conditional allele of Wnk1 (Wnk1fl/+), mice with a deleted allele of Wnk1 (Wnk1fl/−), and mice with a kinase-inactive allele of Wnk1 (Wnk1fl/D386A) with a retrovirus expressing the MLL-AF9 oncogene (Fig. 3a). This evidence concerns the gene MLLT3 and acute myeloid leukemia.