The SET-CAN/NUP214 fusion gene resulting from chromosomal del(9)(q34.11q34.13) or t(9;9) (q34;q34) has been found in T-cell acute lymphoblastic leukemia (T-ALL), B-cell acute lymphoblastic leukemia (B-ALL), acute myeloid leukemia (AML) and myeloid sarcoma (MS). The gene discussed is SET; the disease is acute lymphoblastic leukemia.