To clarify these issues, we employed chromatin immunoprecipitation with high-throughput sequencing (ChIP-seq [28]) and determined genome-wide sites of enrichment for AML1, AML1-ETO, N-CoR, and p300 in Kasumi-1 cells, a model system for t(8;21) leukemia [29]. The gene discussed is RUNX1T1; the disease is leukemia.