Finally, the complement-dependent cytotoxicity induced by anti-PSGL-1 antibodies was evaluated: KPL-1 was not able to induce complement activation on ALCL cell lines; on the contrary, TB5 activated the complement system and induced around 20% cell lysis, but, as expected, its activity was partially neutralized by the presence of membrane complement regulatory proteins on ALCL cells. The gene discussed is SELPLG; the disease is anaplastic large cell lymphoma.