人FLT3(fms-like tyrosine kinase 3)基因是Ⅲ型受体酪氨酸激酶(receptor tyrosine kinase,RTK)家族成员之一。在正常人骨髓中,FLT3基因的表达仅限于CD34+干/祖细胞,其与多种胞浆蛋白作用介导一系列细胞内信号传导,促进细胞的增殖与分化[1]。FLT3内部串联重复(internal tandem duplication,ITD)突变是FLT3基因常见的一种突变类型,具有FLT3-ITD突变(FLT3-ITDm+)的急性髓系白 Human FLT3 (fms-like tyrosine kinase 3) gene is a member of type III receptor tyrosine kinase (RTK) family. In normal human bone marrow, the expression of FLT3 gene is limited to CD34+ stem/progenitor cells, which mediates a series of intracellular signal transduction with a variety of cytoplasmic proteins and promotes cell proliferation and differentiation [1]. FLT3 internal tandem duplication (ITD) mutations are a common mutation type of the FLT3 gene and acute myeloids with the FLT3-ITD mutation (FLT3-ITDm+)