MLLT6 and acute myeloid leukemia: AML cases (n = 539) displayed 16 KMT2A-MLLT4, 14 KMT2A-MLLT3, 11 KMT2A-MLLT10, 4 KMT2A-MLLT1, 4 KMT2A-ELL, and 2 KMT2A-MLLT6 fusions.