For example, several AMLs from the TP53, NPM1, and AML-MR subtypes contained mainly cells resembling mature monocytes, whereas other cases of the same subtype contained mainly cells resembling immature or a mixture of immature and mature cells (Fig. 2a, Supplementary Figs. 6–8), suggesting the presence of significant biological differences beyond current genomic classification schemes. The gene discussed is NPM1; the disease is acute myeloid leukemia.