In the case of AML1‐ETO AML, the RUNX1‐ETO fusion protein limits chromatin accessibility at the LOUP locus and causes inhibition of PU.1 expression, thus halting the tumor suppressor role of LOUP and causing differentiation block and increased proliferation (Trinh et al., 2021). This evidence concerns the gene RUNX1T1 and acute myeloid leukemia.