EGFR and neoplasm: Bevacizumab, a VEGF inhibitor, is approved for recurrent GBM and effectively delays disease progression; however, its impact on OS remains limited.381 Similarly, RTK inhibitors targeting PDGFR (e.g., olaratumab and crenolanib) and c-KIT (avapritinib) show promising BBB penetration but are hindered by resistance mechanisms.382 EGFR inhibitors such as gefitinib, cetuximab, and ABT-414 have demonstrated variable efficacy, primarily due to tumor heterogeneity and adaptive resistance.