CD274 and non-Hodgkin lymphoma: However, the phenotype and clinical significance of programmed cell death 1 (PD‐1) and its ligands, PD‐L1 and PD‐L2, in aggressive acquired immunodeficiency syndrome (AIDS)‐related non‐Hodgkin lymphoma (AR‐NHL) remain poorly understood, particularly in the Epstein–Barr virus (EBV)‐positive subset.