Several biomarkers for PCNSL have been suggested, including multiple myeloma oncogene 1/interferon regulatory factor 4 (MUM1/IRF4), B-cell lymphoma-6 (BCL-6) and CD68, but their major limitation is that it is difficult to use those biomarkers as a potential therapeutic target [4–6]. The gene discussed is CD68; the disease is primary central nervous system lymphoma.