Further study indicated that the proportion of CD3+CD8+IFN-γ+ T cells (Teff cell) in orthotopic drug-resistant GBM tissue in normal saline, Fe3O4-siPD-L1, Fe3O4-siPD-L1@M-BV2 (0.3 mg/kg) and Fe3O4-siPD-L1@M-BV2 (1 mg/kg) treatment group was 3.10%, 13.43%, 19.25% and 23.1%, respectively. The gene discussed is CD8A; the disease is glioblastoma.