Consistent with a feedback loop in which RUNX1 is upregulated in response to decreased CBF activity, the highest levels of RUNX1 expression were detected in CBFB::MYH11 AML, and other cases with loss-of-function mutations in either RUNX1 (923.0 ± 471.5; Figure 7D; red squares indicate biallelic mutations) or CBFB (889.0 ± 305.5). This evidence concerns the gene CEBPZ and acute myeloid leukemia.