This frequent up-regulation of PD-L1 by EBV+ lymphoma cells, and the inhibition of EBV-induced lymphomagenesis following PD-1/PD-L1 blockade in a mouse model [62], suggest a link between EBV infection and PD-1/PD-L1 upregulation. This evidence concerns the gene PDCD1 and Epstein-Barr virus infection.