ARHGEF2 and glioblastoma: In more detail, while NTRK rearrangements are very rare, being found in <2% of GBM cases and consisting of fusions between NTRK1 and other genes, such as NFASC, BCAN, CHTOP, and ARHGEF2, EGFR in-frame fusions are much more frequent (EGFR-SEPT14 and EGFR-PSPH fusion genes were observed approximately in 4 and 2% of cases) and frequently lead to EGFR overexpression in GBM (8); however, all clinical trials with EGFR inhibitors did not demonstrate longer survival times in GBM patients so far, probably due to the inclusion of poorly homogeneous patient populations.