We assessed the real-time interaction between LRIG1 and RTKs, using a nanoluciferase-based complementation assay (NanoBiT, Promega)24 in GBM cells transfected with plasmids encoding for AXL or LRIG1, both C-terminally fused to a part of the luciferase enzyme (LgBiT or SmBiT; Figure 4C). Here, AXL is linked to glioblastoma.