In our study, we confirmed that the miR-21 and CXCR4 expressions were significantly upregulated in glioma tissues compared to normal tissues and cells, which suggested that miR-21 and CXCR4 might play important roles in mediating malignant glioma aggressiveness, as well as the tumorigenicity. The gene discussed is CXCR4; the disease is glioma.