FLT3 and acute lymphoblastic leukemia: Moreover, TCR rearrangements and NOTCH1 mutations were frequently lacking in these patients; together with the low GATA3 expression, these data suggest that the leukemic transformation in FLT3 mutated ETP-ALL might occur at a stem cell pluripotent stage, reflecting a possibly even more immature nature of this ETP-ALL subgroup [20].