GFRA1 and osteosarcoma: Dual-luciferase reporter assay showed that the luciferase activity conspicuously decreased in U2OS/DXR and MG63/DXR cells co-transfected with miR-381-3p and GFRA1 3′-UTR-WT, whereas it remained unchanged in the abovementioned cells co-transfected with miR-381-3p and GFRA1 3′-UTR-MUT, demonstrating that miR-381-3p directly bound to GFRA1 in osteosarcoma cells (Figure 6b and c).