In a phase I trial in R/R FLT3 mutated AML, patients received idarubicin 12 mg/m2 for 3 days with HDAC, 5 g/m2 for 4 days, or 3 days in older than 60 years), followed by crenolanib starting on D5 and continued until 72 h [66]. The gene discussed is HDAC9; the disease is acute myeloid leukemia.