The fact that plasma-induced platelet apoptosis was maximal in the presence of normal CD3+ cells points to antibody-dependent cell cytotoxicity as the mechanism underlying this phenomenon, suggesting that, besides the already reported direct CD8+ cytotoxic effect, T-cells may mediate ITP platelet destruction by an antibody-dependent mechanism. The gene discussed is CD8A; the disease is autoimmune thrombocytopenic purpura.