ID1 and neoplasm: A significant decrease in tumor volume was observed in mice injected with Id1sh LLC cells that received anti-PD-1 agent compared with that seen in mice injected with Id1 or PD-1 inhibition alone or that seen in the control group; and, after day 14, p-values for the groups were as follows: Id1sh/DPBS p = 0.0384; pLKOsc/anti-PD-1 p = 0.0012; pLKOsc/DPBS p = 0.0017 (Figure 2B,C).