FUT4 and mixed phenotype acute leukemia: Figure 13 presents a case of B/megakaryocytic MPAL (biphenotypic) with complex karyotype in a 6-year-old female with PB/BM involvement of neoplastic blasts that express CD34, TdT, B-cell markers (CD19 and CD79a), and megakaryocytic markers (CD41 and CD61), but lack cCD3/sCD3, CD13, CD15, CD117, glycophorin A, or MPO.