FLT3 mutations (D835 and ITD) are detected in patients with leukemia with mixed-lineage leukemia-rearrangement (MLL-r), caused by a translocation of H3K4 methyltransferase (H3K4HMT) MLL1 (also known as KMT2A) [6, 7]. The gene discussed is KMT2A; the disease is leukemia.