<qa>  What is the cytoplasmic CD56?1. Histologically proven extranodal NKT-cell lymphoma, nasal type according to the WHO classification must be pathology-proven EBV DNA positive as well as cytoplasmic CD3 , while CD56 is not an essential diagnostic criteria. . Both newly diagnosed patients and who were previous chemotherapy-treated patients with residual or recurrent diseases will be allowed. 