FLT3 and acute myeloid leukemia: There were two types of NPM1 mutations: type A (c.863_864insTCTG) was found in 71.7% and 65.6% of FLT3-ITD and wild-type FLT3 while type B (c.863_864insCATG) was found in 28.3% of FLT3-ITD and 34.4% of wild-type FLT3 AML.