NPM1 and leukemia: In HOVON-SAKK trials, a positive MRD result after induction chemotherapy is defined as ≥0.1% of CD45-expressing cells with a leukemia associated immunophenotype (LAIP) for MFC-MRD or, for AML with mutated NPM1, >10−4 NPM1 copies using reverse transcriptase polymerase chain reaction.