PDCD1 and neoplasm: When a PD-1:PD-L1 interaction dependent CD8+ T cell influx was incorporated, the increase in CTL concentration due to anti-PD-(L)1 treatments significantly increased (from 2.8% to 65000% for anti-PD-1, and from 56% to 208000% for anti-PD-L1), as did the reduction in tumor volume (from 0.017% to 35% for anti-PD-1, and from 52% to 75% for anti-PD-L1) (Figures 1C,D).