In contrast, the percentage of CD8+ CTL in the secondary tumours of mice after the PLGA-ICG-R837-based PTT plus anti-CTLA-4 treatment significantly increased to ∼19.7%, which appeared to be higher than that in groups treated with PLGA-ICG-R837-based PTT (∼8.96%) or surgery plus anti-CTLA4 treatment (∼12.96%) (Fig. 4a,c). This evidence concerns the gene CTLA4 and neoplasm.