NPM1 and acute myeloid leukemia: This finding reflects previous observations from our and other groups on the high frequency of IFNγ-producing NPM1mut-specific T cells in the peripheral blood of healthy volunteers or AML patients after HSCT [16,40], possibly due to a cross-reactive immune response induced by short amino acid sequences from the C-terminal of NPM1-mutated protein homologous with several common viral and bacterial antigens [16].