BCL6 and primary central nervous system lymphoma: We studied the prognosis of the relative expression profile of target genes of NFkB pathway (MYC, BCL2), the essential transcriptional regulator in hematopoiesis LMO2, the checkpoint regulation pathway MGMT, the transcription factor POU2F1, the immune checkpoint gene PDCD1, and the proto‐oncogene and transcriptional repressor gene BCL6 and its proteins in PCNSL.