 Along a 5-year period in a single institution, specific molecular markers were prospectively looked for in consecutive patients with acute leukemia, by means of polymerase chain reaction (PCR): In patients with acute lymphoblastic leukemia (ALL), the BCR/ABL and TEL-AML1 fusion transcripts as well as clonotypic immunoglobulin gene rearrangements were investigated, whereas in patients with acute myelogenous leukemia (AML) the PML-RAR alpha, AML1-ETO and CBF beta-MYH11 fusion proteins were assessed. 