CD274 and lymphoproliferative syndrome: These include EBV+ plasmablastic lymphoma (PL) (where 20% of tumor cells are PD-L1+) [58], EBV+ post-transplant lymphoproliferative disorders (PTLD) (where 60% of tumor cells are PD-L1+) [13], EBV+ DLBCL of the elderly (where 100% of tumor cells are PD-L1+) [13] and the recently described EBV+ DLBCL subtype [31] found in young patients (where 76% of patients display an expression of PD-L1 by more than 5% of their tumor B cells) [61].