We were able to directly tie increased G-CSF release to enhanced cell proliferation of t(8;21)(q22;q22.1) AML cells harboring BRCC3 WT, but not to other cell lines with a different cellular background including inv(16)(p13.1q22), which further links BRCC3 mutations to t(8;21)(q22;q22.1) AML. This evidence concerns the gene CSF3 and acute myeloid leukemia.