We demonstrated that FOXM1 inhibitors suppressed growth and induced apoptosis of human MLL-r leukemia cell lines but had much less effect or had a marginal effect on survival and growth of non-MLL-r leukemia cell lines such as K-562, Kasumi-3, HL-60, and U-937 when all cells were treated with FOXM1 inhibitors under the same condition. The gene discussed is KMT2A; the disease is leukemia.