KLRD1 and neoplasm: Studies have demonstrated that the prognosis of patients is associated with numerous factors, including bone marrow infiltration, tumor invasion, existence of group B symptoms (fever >38°C for >3 days, night sweats and weight loss of >10% in six months), EBV DNA level of circulating blood (53), granzyme B, CD94, Ki-67 expression and hemoglobin concentration prior to treatment (54).