NPM1 and acute myeloid leukemia: A bone marrow biopsy unveiled 25% myeloblasts in the marrow aspirate (Figure 2C, 2D), with flow cytometry showing FMS-like tyrosine kinase 3 (FLT3) and nucleophosmin (NPM1) mutations, confirming the diagnosis of a second primary malignancy, acute myelogenous leukemia (AML).