Irs-4 has also been implicated in the insulin-dependent proliferation of a murine T-cell lymphoma cell line and it is overexpressed in a pediatric T-cell acute lymphoblastic leukaemia (T-ALL) that harbors a breakpoint fusion between the T-cell receptor beta locus and the IRS-4 gene [99,100]. The gene discussed is IRS4; the disease is T-cell acute lymphoblastic leukemia.