To test whether NPM1 expression depends on the mutation status, we divided the studied leukemia samples into the following groups: (i) NPM1-mut leukemia (with a tetranucleotide insertion in exon 12 of the NPM1 gene, 15 samples) vs. leukemia without an NPM1 mutation (wt, 51 samples); (ii) FLT3-mut leukemia (with FLT3-ITD, 9 samples) vs. leukemia without a FLT3 mutation (wt, 57 samples); and (iii) leukemia with a RUNX1/RUNX1T1 fusion gene, generated as a result of translocation t(8;21) (4 samples) vs. leukemia samples without this translocation (wt, 62 samples). The gene discussed is FLT3; the disease is leukemia.