By comparing the expression levels of β-catenin (Fig. 6b, c), the proportion of CD8+ T cells and the rate of IFN-γ+ CD8+ T cells (Fig. 6d, e) in CTRL + Vehicle, NE + Vehicle, NE + Prop + Vehicle, anti-PD-1 mAb + NE + Vehicle and anti-PD-1 mAb + NE + Prop + Vehicle tumours, we found that Prop antagonised NE to up-regulate β-catenin expression and inhibit CD8+ T-cell infiltration and function. This evidence concerns the gene PDCD1 and neoplasm.