Shi et al. (2018) used immunohistochemistry to analyze 20 PBL cases, including 11 PBL not otherwise specified (PBL NOS), 5 HIV+ PBL, 2 ALK+ large B cell lymphomas (LBCL), 1 primary effusion lymphoma, and 1 PBL with angioimmunoblastic T cell lymphoma (AITL). The gene discussed is ALK; the disease is angioimmunoblastic T-cell lymphoma.