NPM1 and acute myeloid leukemia: NPM1 is one of the most frequently mutated gene in NK AML (50% of NK AML cases), with the insertion of 4 nucleotides in the 3’end of the mature transcript observed in more than 95% of NPM1-mutated cases and leading to a neomorphic protein with aberrant cytoplasmic localization (NPM1c) [9, 14, 15].