TNFRSF21 and diffuse large B-cell lymphoma: DLBCL associated with viral agents (EBV-associated, HHV-8-associated) are rare and, in most instances, their diagnosis is based on the clinical presentation and pathological features; a set of mutated genes possibly specific for this disease has been described in EBV-positive DLBCL, including CCR6, CCR7, DAPK1, TNFRSF21, CSNK2B and YY1 [80], as well as common PD-L1 genetic aberrations [81]