GPC2 and central nervous system cancer: Future efforts should focus on: Developing ECM-targeted CAR T cell therapies, leveraging CSPG4, BCAN, and GPC2 as established ECM antigens; incorporating ECM-modifying enzymes (e.g., heparanase) into CAR T cell constructs to enhance tumor penetration; and investigating ECM-immune interactions to identify strategies that convert gliomas from immune-cold to immune-hot tumors.