FLT3 and acute myeloid leukemia: Additionally, we assessed OSM levels in the plasma of AML patients and observed substantially higher levels in patients with FLT3-ITD+ AML and active disease (i.e., initial diagnosis, blast persistence, or relapse) than in FLT3-ITD+ patients in remission or in FLT3-ITD- patients (Fig. 2c; supplementary Table 2).