PDCD1 and neoplasm: As shown in Fig. 8D, at the endpoint (PG-D19), tumor volume of the vehicle group was 2003.28 ± 186.55 mm3; the tumor volumes of the ZGGS15 low-dose (1.5 mg/kg), high-dose (5 mg/kg) groups, anti-PD-1 antibody (1 mg/kg) group, ZGGS15 low-dose plus anti-PD-1 antibody (1.5 mg/kg + 1 mg/kg) and ZGGS15 high-dose plus anti-PD-1 antibody (5 mg/kg + 1 mg/kg) were 1000.18 ± 215.43 mm3, 1160.76 ± 194.85 mm3, 814.21 ± 232.43 mm3, 600.23 ± 107.03 mm3 and 384.95 ± 181.10 mm3, respectively.