TCF3 and acute lymphoblastic leukemia: To check for submicroscopic aberrations associated with T-ALL, FISH analysis for the following loci were performed: MLL, c-myc, bcr, TCF3 (all from DAKO, Denmark), SIL/TAL1, and T-cell receptor loci α/δ, β and γ (all from Abbott Molecular, Germany) of which all were negative.