Regardless of the tumor tissue or spleen, CD8+ meso CAR-T cells with SFN pre-treatment or exogenous SFN administration showed less PD-1 expression and stronger IFN-γ and IL-2 secretion ability compared with untreated meso CAR-T cells, while exhibiting no significance compared to treatment with meso CAR-T cells plus anti-PD-1. Here, PDCD1 is linked to neoplasm.