In T-ALL, different subtypes are characterized by sequence mutations or copy number alterations in, e.g., NOTCH1 or FBXW7 as well as subtypes showing deregulated expression of genes encoding specific transcription factors (e.g., TAL1, LMO1, LMO2, TLX3 and MYC), generally due to chromosomal deletions [200]. This evidence concerns the gene TAL1 and acute lymphoblastic leukemia.