In particular, relevant to the use of PD-1/PD-L1 inhibitors in cancer immunoherapy, it will be interesting to verify the differential expression of PD-L1 on DC subsets in the tumor microenvironment, which may contribute to PD-L1 upregulation on DCs through the action of various factors including IL-10, as used in our study, and tumor growth factor (TGF)-β (56). Here, TGFB1 is linked to cancer.