RUNX2 and acute myeloid leukemia: In order to identify the breakpoint of t(6;8)(p21;q24), we performed fluorescent in situ hybridization (FISH) utilizing three distinct probes against either the 5′ region of MYC (8q24), 1.7-Mb 3′ downstream region of MYC (8q24), which contains blood cell-specific MYC enhancers in normal cells and AML cells24,29,30, or a coding region of the RUNX2 gene (6p21) in a patient and CAL-1 cells (Fig. 1d).