GRB2 and hepatocellular carcinoma: Dual luciferase reporter assay results showed that firefly luciferase reporter activity was significantly reduced in HCC cells co-transfected with pCMV-GRB2-WT vector and miR-1271 mimics compared to cells co-transfected with pCMV-GRB2-Mut vector and miR-1271 mimics (Figure 5E).