Different prognostic value of FLT3-ITD allelic burden according to underlying NPM1 mutational status. Thus, in patients with mutated NPM1, a similar (A) survival and (B) relapse risk were observed between patients without FLT3-ITD and low ratio FLT3-ITD/wt (<0.5), whereas patients with a high FLT3-ITD/wt ratio showed a worse prognosis. In contrast, among wild-type NPM1 AML patients, the presence of FLT3-ITD was associated with a worse outcome compared with those without FLT3-ITD, regardless FLT3-ITD/wt mutational load, both in terms of (C) survival and (D) relapse risk.