AML cells prevent against drug cytotoxicity by rapidly increasing the level of protective cholesterol, which is achieved by elevating the HMGCR and LDL-R mRNA levels.8 Our data further demonstrated that OE of HMGCS1, another gene upstream in the cholesterol synthesis pathway in leukemia cells could endow them with resistance to chemotherapeutic drugs. This evidence concerns the gene LDLR and leukemia.