BIRC5 and glioblastoma: The inverse correlation between the expression of miR-138 and BIRC5 suggests a possibility that miR-138 directly target BIRC5. In western blotting on GBM cell lysates, transient overexpression of miR-138 showed a significant reduction of the Survivin expression compared to GBM cells treated with miR-Ctrl (GBM12, 28 and 43) (Figure 4A).