The FLT3 gene helps stem cells mature to red blood cells, white blood cells and platelets in a process known as differentiation. The gene also helps control the number of cells produced.

But if development of the stem cells stops, the gene can mutate. “A large number of these poorly differentiated cells can transition into acute leukemia,” says Naval Daver, M.D.

30% to 35% of patients with acute myeloid leukemia (AML) carry...