PDCD1 and melanoma: In the B16F10 melanoma model, SB-3CT alone significantly decreased tumor growth at day 9 after treatment (mean tumor size 1469 vs 2030 mm3; p < 0.01 by two-way analysis of variance (ANOVA), Tukey’s multiple comparison test; Fig. 2a, c), while a combination treatment of SB-3CT and anti-PD-1 achieved better efficacy (mean tumor size 339 vs 2030 mm3; p < 0.001; Fig. 2a, c).