This proportion can be potentially increased using the newly identified mutated genes such as FLT3 and NPM1 as well as over-expressed genes such as WT1. MRD monitoring with flow cytometry relies on the idea that AML cells frequently have aberrant antigen expression resulting from asynchronous antigen-expression, cross-lineage antigen expression, antigen over-expression, and aberrant light scatter properties. This evidence concerns the gene NPM1 and acute myeloid leukemia.