Despite these controversies it has been shown that when xenografted into severe combined immunodeficient mice, 518A2 human melanoma cells with silenced bcl-2 either failed to grow at all or grew to tumors of low volume and then completely regressed; whereas control cells with normal levels of Bcl-2 protein expanded to be large, necrotic tumors [10]. The gene discussed is BCL2; the disease is melanoma.