In a large series of AML patients treated by intensive chemotherapy, ~10% of the patients were noted to have fever, very high serum ferritin levels and bone marrow hemophagocytosis accompanied by hepatomegaly, pulmonary or neurological symptoms, liver abnormalities, a lower platelet count, higher levels of C-reactive protein and prolonged pancytopenia. The gene discussed is CRP; the disease is acute myeloid leukemia.