In this present study, the levels of IL-16 in the plasma and bone marrow supernatants and mRNA expression of pro-IL-16, caspase-3 and T-bet in the peripheral blood mononuclear cells (PBMCs) and bone marrow mononuclear cells (BMMCs) of patients with ITP were determined. The gene discussed is CASP3; the disease is autoimmune thrombocytopenic purpura.