NPM1 and acute myeloid leukemia: We hypothesized that higher NPM1 levels in the nucleoplasm of NPM1-mutated AML cells (secondary to the aberrant localization of mutant NPM1 as well as, through heterodimerization, of wild-type NPM1) may facilitate nucleolar stress response and increase sensitivity to dactinomycin in NPM1-mutated AML cells [24].