A total of 46 DNA and cDNA diagnosis samples, 102 DNA and cDNA post-allo-HSCT samples from 34 patients and 37 cDNA samples from 7 patients with refractory/relapse AML treated with FLT3i were assessed for the FLT3-ITD mutation through fragment analysis. Here, FLT3 is linked to acute myeloid leukemia.