To confirm our findings that GzB knock-down reduces the sensitivity of ALK+ ALCL cell lines to staurosporine-induced apoptosis and to better quantify this difference, we examined the effect of GzB knock-down on the degree of terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL)-positive staining in ALK+ ALCL cell lines treated with staurosporine. The gene discussed is ALK; the disease is anaplastic large cell lymphoma.