CXCL12 induces VEGF secretion through CXCR7 in SMMC-7721 cells. SMMC-7721 cells were plated in the 24-well plates. SMMC-7721 cells were serum starved for 24 h, and the cells were treated with CXCL12 (100 ng/ml). The cultured supernatants were harvested 24 h after treatment, and VEGF was measured by ELISA assay. VEGF secretion of SMMC-7721 cells increased significantly after treatment with CXCL12 for 24 h. Cells transfected with CXCR7shRNA displayed decreased VEGF secretion compared with control and NC cells. Each bar represents mean ± SD from three independent experiments. *p < 0.05 (as compared with control cells).