FLT3 and acute lymphoblastic leukemia: Comparing GATA3low and GATA3high ETP-ALL, we found FLT3 mutations (including both internal tandem duplications and mutations in the tyrosine kinase domain) in 79 % of GATA3low ETP-ALL (15/19), while only 15 % of GATA3high ETP-ALL (7/46) were FLT3 mutated (p < 0.001).