RUNX1 and acute myeloid leukemia: To confirm the presence of CTCF at these loci in primary AML cells, we performed CTCF ChIP-seq on primary AML patients with the NPM1c insertion mutation in NPM1, t(9;11) and t(11;19) MLL rearrangements, and t(8;21) creating the RUNX1-RUNX1T1 gene fusion, which displayed the expected HOXA and HOXB, HOXA only, and no HOX expression patterns, respectively (Table S1 and Fig. S1A).