HOXA1 and acute myeloid leukemia: There were more statistically supported chromatin loops in the NPM1-mutant AML sample compared with the RUNX1-RUNX1T1 sample (5 vs. 3), and the region of the HOXA cluster that interacted with intron 1 of SKAP2 involved posterior HOXA genes in the NPM1c sample, but was restricted to the anterior HOXA1 gene in the RUNX1-RUNX1T1 sample (Fig. 6c).