“…These studies encompassed 27 PCNSL and 42 SCNSL, with sample sizes ranging from 2 to 14. Patients underwent CAR T-cell monotherapy in six studies ( Frigault et al, 2019 ; Ahmed et al, 2021 ; Ghafouri et al, 2021 ; Roddie et al, 2021 ; Frigault et al, 2022 ; Zhang et al, 2022 ) and ASCT combined with CAR T-cell therapy in one study ( Wu et al, 2021 ), while diverse treatments containing CAR T-cell therapy were employed in the remaining five studies ( Li et al, 2020 ; Siddiqi et al, 2021 ; Liu et al, 2022 ; Xue et al, 2022 ; Lacan et al, 2023 ). For co-stimulation domains, two studies used CD28 ( Ghafouri et al, 2021 ; Siddiqi et al, 2021 ), six studies used 4-1BB ( Frigault et al, 2019 ; Roddie et al, 2021 ; Frigault et al, 2022 ; Liu et al, 2022 ; Xue et al, 2022 ; Zhang et al, 2022 ), two studies contained both CD28 and 4-1BB ( Ahmed et al, 2021 ; Lacan et al, 2023 ), and two studies used CD28/4-1BB ( Li et al, 2020 ; Wu et al, 2021 ).…”