Firstly, copy number alterations (amplifications or gains) and/or translocations involving 9p24.1/PD-L1/PD-L2 are associated with PD-L1 overexpression in tumor cells of classical Hodgkin lymphoma (CHL), primary mediastinal large B cell lymphoma (PMBL), Epstein-Barr virus (EBV)-negative primary central nervous system lymphoma (PCNSL), primary testicular lymphoma (PTL), and in a subset of diffuse large B cell lymphoma (DLBCL) [90–94]. Here, CD274 is linked to classic Hodgkin lymphoma.