CXCL12 and primary central nervous system lymphoma: In the perivascular TME, CXCL9 can form heterocomplex with B-cell chemoattractant CXCL12 to enhance CXCL12-induced CD8+ T cell as well as malignant B cell recruitment toward BV walls in the primary central nervous system lymphomas (Venetz et al., 2010).