Breakthrough of the last decade, the immune checkpoint inhibitors against cytotoxic T lymphocyte associated protein 4 (CTLA-4), programmed death 1 (PD-1) and programmed death ligand 1 (PD-L1) have shown unprecedented antitumor effect in particular against advanced melanoma or non-small cell lung cancer20,21. Here, CTLA4 is linked to melanoma.