The exception to the 220% standard was CBF acute myeloid leukemia including cytogenetic abnormalities (t [8; 21], or inv [16], or t [16; 16]), NPM1 mutant AML, or acute promyelocyte leukemia; in each case, the diagnosis of acute myeloid leukemia was not dependent of % of blast seen. The gene discussed is NPM1; the disease is acute promyelocytic leukemia.