NTRK1 and acute myeloid leukemia: Activating mutations of the FMS-related tyrosine kinase 3 (FLT3) receptor gene leads to constitutive activation of the FLT3 receptor tyrosine kinase and results in autonomous, cytokine-independent proliferation in vitro, which are the most common somatic mutations observed in acute myeloid leukemia (AML)1.