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). The gene discussed is RUNX1; the disease is acute myeloid leukemia.