CXCR4 and neoplasm: MIF upregulates synovial fibroblast matrix metalloproteinase expression levels, which can promote tissue degradation and cell migration.63 In meningioma, co-expression of MIF with matrix metalloproteinase-9 was associated with increased tumor invasion and recurrence.64 In glioblastoma, MIF activates CXCR4 to promote a mesenchymal phenotype and contribute to tumor invasion.65