NPM1 mutations in AML: does size matter?

In this issue of Blood, Gil et al 1 demonstrate that NPM1-mutated acute myeloid leukemia (AML) with a lower disease burden defines a distinct subset with secondary AML features and inferior survival.Furthermore, they show that mutation order of acquisition and clonal composition modulate prognosis of NPM1-mutated AML.These findings could ultimately refine risk stratification of NPM1-mutated AML.