B cell expressed Fas-L has been implicated in the induction of TH cell apoptosis in HIV and EBV infections [60], and Fas-L expression on malignant B cells in lymphoid cancers such as chronic lymphocytic leukemia (CLL) may play a role in inhibiting anti-tumor responses by inducing TH cell apoptosis [61]. Here, FASLG is linked to Epstein-Barr virus infection.