We found that SIL-TAL1+ T-ALL was characterized by higher white blood cell count (P = 0.029) at diagnosis, predominant cortical T-ALL immunophenotype (P = 0.028) of the leukemic blasts, and a higher prevalence of tumor lysis syndrome (TLS, P<0.001) and disseminated intravascular coagulation (DIC, P<0.001), which led to a higher early mortality (P = 0.011). This evidence concerns the gene TAL1 and Tumor Lysis Syndrome.