STAT5A and leukemia: Since the past findings suggested that gilteritinib ameliorates hyper-activated intracellular signaling-mediated STAT5A, RAS, MEK, and PI3K/AKT by silencing the tyrosine kinase activity of mutated FLT3 [18], we presumed that the disturbed intracellular signalling in leukemia cells of the patient was improved, at least in part, as the initial dose appeared partially effective to attenuate the disease progression.