Recently, Hornung et al. identified that expression of CD109, HOPX, and KIAA0125 genes might be responsible for inferior survival in AML patients with RUNX1 mutations but, on the other hand, better outcome in RUNX1/RUNX1T1 fusion through a newly proposed statistical tool “mediation analysis.” The three genes’ expression levels were significantly higher in patients with RUNX1 mutant but lower in those with RUNX1/RUNX1T1 fusion [61]. The gene discussed is RUNX1; the disease is acute myeloid leukemia.