Down-regulated LINC00899 promotes cell apoptosis. a, Flow cytometry map demonstrating cell apoptosis conditions of spinal ependymoma cells by the flow cytometry analysis of Annexin V-FITC/PI staining; b, apoptosis rate for spinal ependymoma cells in response to the treatment of LINC00899 vector, siRNA-LINC00899, siRNA-RBL2 and siRNA-LINC00899 + siRNA-RBL2; *, p < 0.05 vs. the blank and NC groups; NC, negative control; PI, propidium iodide.