TAL2, a transcription factor of the basic helix-loop-helix family, was activated at the junctions of chromosomal translocations associated with T-cell acute lymphoblastic leukemia causing overexpression in the T-cell lineage, identifying TAL2 as an oncogenic transcription factor of T-ALL59, 60. This evidence concerns the gene TAL2 and T-cell acute lymphoblastic leukemia.