ERBB2 and central nervous system neoplasm: While preclinical studies such as those incorporating HER-2 targeting CAR-T cells and non-engineered cytotoxic lymphocytes (CTLs) in murine GBM models have demonstrated that intranasal delivery of immune cells can lead to migration within brain regions affected by disease, this method is still in its early stages, and requires rigorous testing to ensure safety and efficacy, particularly given the heterogeneous nature of BBB disruption across various CNS tumor variants (21).