PDCD1 and neoplasm: CD8+ T cells were divided into 4 groups and co-raised with different immune checkpoint inhibitor drugs (including anti-PD1, anti-TIM-3, anti-PD1+ anti-TIM-3 and control groups) for 1 hour, and then co-cultured with tumor cells for 24 hours and detected the apoptotic ratio of tumor cells (Fig. 5F).