Fig. 3.

Illustrates the FRET-based approach for detecting protein–protein interactions. Using FRET-based probes, glioma cells that invade the brain parenchyma have higher Rac1 and Cdc42 activity and lower RhoA activity than cells that penetrate the perivascular area. In other words, the FRET-based method was useful for monitoring the invasion mode of GBM cells. This can be controlled by balancing the activity of Rho-family GTPase and Cdc42-specific GEF