Limited dilution series for the assessment of sensitivity and specificity of NPM1 mutations. cDNA from time point of diagnosis was diluted in an NPM1-unmutated cDNA. (A) An example of a patient with NPM1 mutation of type A is shown. This mutant shows high specificity and sensitivity. (B) In type D, a coamplification of wild-type NPM1 was observed (indicated by ), leading to reduced sensitivity.