Two-hundred and ten (46.5%) of 452 FLT3-ITD + AML patients had one ITD, and 242 (53.5%) harbored more than one ITD (2 ITDs, n = 131 [29%]; 3 ITDs, n = 58 [13%]; 4 ITDs, n = 24 [5%]; 5 ITDs, n = 18 [4%]; 6 ITDs, n = 3 [1%]; 7 ITDs, n = 7 [2%]; 9 ITDs, n = 1 [0.2%]). The gene discussed is FLT3; the disease is acute myeloid leukemia.