NPM1 and acute myeloid leukemia: Recent studies have reported that combinations of the most common mutated genes, that are of prognostic value in AML, including Fms-like tyrosine kinase 3 - internal tandem duplication (FLT3-ITD), nucleophosmin 1 (NPM1) and DNA methyltransferase 3A (DNMT3A), usually co-exist in different subclones within the same patient and are prone to cause chemo-refractoriness or early relapse5–7.