LRIG2 and glioblastoma: After the Flag-fusion soluble LRIG2 ectodomain were down-regulated from the supernatants, the effects of conditioned medium on the proliferation of U87 cells were abrogated (Figure 3B, 3C), which indicated that the soluble LRIG2 ectodomain in the conditioned medium exerted proliferative effects on the glioblastoma cells.