Gene expression profiling of human T-ALL samples, distinguishes different stages of arrest during T-cell development: (i) early immature T-ALLs at the DN stage, opposed to (ii) CD1a+/CD4+/CD8+ or CD3+/CD4+/CD8+ T-cells, respectively, in early-cortical and late-cortical thymocyte T-ALLs [43]. This evidence concerns the gene CD8A and acute lymphoblastic leukemia.