The tumor microenvironment in the 2 EBV tissue-positive PCNSL subtypes and EBV⁻HIV⁻PCNSL. A targeted gene expression panel was chosen of selected clinically pertinent immune effectors, macrophages, and immune-checkpoint markers. Gene counts are shown for each PCNSL subtype, with P values for paired subtypes: *P ≤ .05; **P ≤ .01; ***P ≤ .001; ****P ≤ .0001. There were 34, 18, and 18 cases of EBV⁻ HIV⁻, EBV⁺ HIV⁺, and EBV⁺ HIV⁻ PCNSL, respectively.