We constructed miR-21 knockdown (anti-miR-21), CXCR4 knockdown (sh-CXCR4), and miR-21 and CXCR4 double-targeted knockdown (anti-miR-21 + sh-CXCR4) U87 and U251 cells to investigate the anti-miR-21 + sh-CXCR4 generated effects on glioma tumorgenicity. Here, CXCR4 is linked to central nervous system cancer.