Acute myeloid leukemia fusion genes can be found in CD33‐negative cells

Introduction Targeted therapies and immunotherapies are emerging strategies for the treatment of leukemia. CD33 is a common and important therapeutic target for cellular immunotherapy or antibody immunotherapy. Drugs on targeting CD33 are also emerging. However, acute myeloid leukemia (AML) relapse still occurs after treatment with targeted CD33, for which the mechanism is unknown. Methods We used fluorescence in situ hybridization and real‐time polymerase chain reaction to detect the expression of fusion genes in different populations of cells from AML patients. Result Fusion gene can be express in CD33 negative cell proportions in newly diagnosed and relapsed AML patients. Conclusion There are fusion genes in CD33‐negative cells that are might not be cleared by CD33 targeting therapy. And this might be the source of relapse.