NPM1 and acute myeloid leukemia: Although both peptides were naturally processed and recognized by specific CD8+ T cells, among 27 NPM1-mutated AML patients a significantly higher frequency of T-cell responses was shown against peptide #3 (44% of patients) compared to healthy subjects (6/33, 18%), whereas for peptide #1 the frequency of specific immune responses found in NPM1-mutated AML and healthy volunteers (33% and 39%, respectively) was not statistically different [16].