PDCD1 and neoplasm: To excavate the potential mechanisms underlying the synergistic effect of IL-23 and PD-1 mAb in anti-tumor immunity, we performed RNA-seq analysis on MDA-MB-231-specific CTLs following the treatment with exogenous IL-23 (50 ng/ml) or PD-1 mAb (30 μg/ml) (Fig. 4A).