Abstract: Leukemia represents a group of diseases of hematopoietic stem/progenitor cells with dynamic changed such as chromosomal translocations and/or gene mutations. Recently,evidences suggest that acute myeloid leukemia follow a "Multi-hit"model in leukemogenesis. Acquisition of GATA-2 mutations other than BCR/ABL fusion gene may cause disease progression from chronic myeloid leukemia to acute transformation. AML1-ETO represents the first, fundamental genetic hit to initiate the disease,wheresa C-KIT mutation may be a second hit for the development of acute myeloid leukemia M2 with t(8;21).TEL-AML1 functions as a first genetic event,the additional loss of the normal TEL allele may cause full-brown leukemia which mainly occurs in childhood acute lymphoblastic leukemia. The new progress of leukemias in pathpgenesis and targeted therapy are summarized.

Key words:

Multi-hit, chronic myeloid leukemia, acute myeloid leukemia M2b, TEL-AML1-associated childhood acute lymphoblastic leukemia