Similarly, Corces-Zimmerman et al. [30] found that NPM1c mutations were absent in purified haemopoietic stem cells, in contrast to putative founder mutations including DNMT3A, IDH1, IDH2 and ASXL1. In cases of AML analysed at the single cell level, Jan et al. [8] (one case) and Quek et al. [16] (three cases) documented that NPM1c was sub-clonal or secondary to TET2 mutations. The gene discussed is DNMT3A; the disease is acute myeloid leukemia.