They found that MLL-AF9 translocations could only cause AML and had no capability to produce ALL even when induced in T cells, MLL-ENL could cause both AML or T-ALL (but not B cell ALL) depending on whether it was expressed in a more primitive or a more differentiated cell, and MLL-AF4 could only produce B cell lymphomas even when induced in T cells [153,154,155,156,157]. Here, AFF1 is linked to acute lymphoblastic leukemia.