[80] provided mechanistic evidence in murine melanoma: CD103+CD8+T cells from tumor‐bearing mice expressed IL‐10, CD25, and CTLA‐4, suppressed CD8+T‐cell proliferation in vitro in a partly PD‐1/PD‐L1–dependent manner, and accelerated tumor growth upon adoptive transfer in vivo. Here, PDCD1 is linked to neoplasm.