UPN09 (Figures 1D, 2) was diagnosed with secondary AML (prior diagnosis of myeloproliferative neoplasm (MPN); AML not otherwise specified (NOS), AML without maturation, normal male karyotype, no BCR–ABL1 fusion, no CEBPA, FLT3, or NPM1 mutation) in 2008. This evidence concerns the gene CEBPA and acute myeloid leukemia.