FGFR1 and glioma: In response to NLGN3, multiple RTKs (VEGFR2, EGFR and FGFR1) as well as Gαi1 and Gαi3 were enriched in the endosomal fraction in P1 glioma cells (Figure 3B), but not in Gαi1/3-silenced cells (Figure 3B).