In addition to either genetically engineered T cells against NPM1-mutated protein [4,20,24] or T cells reactive against patients’ primary blasts [66,67], the observation of spontaneous development of specific anti-leukemic T cell immunity directed against highly immunogenic NPM1-mutated peptides could also indicate the feasibility of stimulating and expanding ex vivo NPM1-mutated specific CTL lines from either patients with NPM1-mutated AML or healthy donors, who may be antigen-naive, to be potentially used for adoptive immunotherapeutic approaches [16,19,42]. The gene discussed is NPM1; the disease is acute myeloid leukemia.