A reduction in cell colonies in colony-forming immunoassays was demonstrated by CTLs against PRAME, RHAMM, and WT1 antigens in both NPM1-mutated and wild-type subgroups, whereas no response was exerted by CTLs against NPM1-mutated epitope in NPM1 wild-type AML cases. This evidence concerns the gene NPM1 and acute myeloid leukemia.