STAT3 and diffuse large B-cell lymphoma: STAT3 is constitutively activated in EBV-positive neoplasms, post-transplant lymphoproliferative diseases (LPDs) [14], EBV-positive diffuse large B-cell lymphoma (DLBCL) [15], nasopharyngeal cancer (NPC) cells [16], and extranodal NK/T-cell lymphoma (ENKL) [17].