Top, Schematic showing therapeutic strategy. Mice were implanted in left (L) and right (R) flanks with B16F10-GP cells (Day 0). Day 10, mice received either: (i) vehicle alone control; (ii) QH-II-066; (iii) α-PD-L1; (iv) QH-II-066+α-PD-L1. Bottom, Effect of combination of QH-II-066 and α-PD-L1 on tumor growth kinetics. In groups receiving QH-II-066, 10 mg/kg was injected i.p. daily for 7 days. In group receiving α-PD-L1, 200 μg was injected i.p. every 3 days through end of the experiment. Tumor measurements were taken with 7–8 mice per group with a tumor on each flank; where, vehicle alone control, n=7; α-PD-L1, n=8; QH-II-066, n=7; QH-II-066+ α-PD-L1, n=7. (*p<0.05; **p<0.01; ***p<0.001; ****p<0.0001). Abbreviation: PD-L1 = programmed death-ligand 1; i.p., intraperitoneal.