PDCD1 and neoplasm: Similarly, systemic i.v. infusion of DNT cells also significantly reduced NCI-H460 tumor volume from 1017.49 ± 246.2 mm3 in the control group to 572.5 ± 186.5 mm3 in the DNT cell treated group, resulting in a 43.7 ± 18.3% reduction in tumor volume, and the combination therapy of i.v. inoculated DNT cells and anti-PD-1 treatment resulted in an additional 32.6 ± 20.0% reduction in tumor volume (from 572.5 ± 186.5 mm3 in the DNT cell alone treated group to 385.9 ± 114.3 mm3 when in combination) by day 20 (Additional file 2: Figure S5B).