BTG1 and primary central nervous system lymphoma: Reportedly, approximately 90% of PCNSL cases are DLBCLs,5 and recent studies have shown an accumulation of mutations in genes such as MYD88, CD79B, TBL1XR1, PIM1, IGLL5, and BTG1 in PCNSL cases.6, 7, 8, 9, 10, 11