Aberrant expression of tumor suppressor genes WT1, RB1, p53, homozygous deletion of p16 gene and their relationship with expression of oncogenes BCR-ABL, TEL-AML1, MLL-AF4, E2A-PBX1, SIL-TAL1 were determined in bone marrow samples of children with de novo B-lineage (n = 170) and T-lineage (n = 25) acute lymphoblastic leukemia (ALL). In contrast to expression of chimeric oncogenes alterations in p16, WT1, RB1 and p53 expression were T/B-lineage-unrestricted. Significant association between expression of MLL-AF4 and WT1, E2A-PBX1 and p53; SIL-TAL1 and homozygous deletion of p16 has been demonstrated. (c) 2005 Elsevier Ltd. All rights reserved.