When sorafenib (400 mg twice a day) was used in a phase II study with azacytidine (75 mg/m2/day × 7 days) in 43 patients with relapsed/refractory AML (40 with FLT3–ITD mutations) [21], an overall response rate (ORR) of 46% was observed. This evidence concerns the gene FLT3 and acute myeloid leukemia.