PDCD1 and neoplasm: Interestingly, in OSCC mice with LD, anti-PD-1 treatment significantly decreased the tumor volume compared with those with no LD (P = 0.002 and < 0.001 for MOC1+LD+αPD-1 and LD+MOC1+αPD-1 vs. MOC1+αPD-1, respectively), which illustrated that LD improved the efficacy of anti-PD-1 immunotherapy in OSCC (Fig. 1C).