Abnormal cholesterol homeostasis is observed in both refractory leukemia patients21 and leukemia cells exposed to chemotherapy.22,23 It is widely accepted that cholesterol consumption is higher,23,24 and cholesterol synthesis is enhanced in most leukemia cells.8,21 These data explain the higher serum cholesterol/lipid levels in RR compared CR patients, probably due to enhanced de novo cholesterol synthesis contributed by an increased HMGCS1 expression level in AML cells. The gene discussed is HMGCS1; the disease is acute myeloid leukemia.