PD-L1 on tumor cells is known to inhibit the activity and toxic effects of CD8+ T cells.20 To measure the function of PD-L1 induced by C-FOXP3, peripheral blood mononuclear cells (PBMCs) or isolated CD8+ T cells (Supplementary Fig. 3) were stimulated by anti-CD3/anti-CD28 antibodies and cocultured with human or mouse PDAC cells. This evidence concerns the gene CD28 and neoplasm.