1. 1) Pardoll, D.M.: The blockade of immune checkpoints in cancer immunotherapy. Nat Rev Cancer. 12: 252-264, 2012.
2. 2) Chen, T.W., et al.: A systematic review of immune-related adverse event reporting in clinical trials of immune checkpoint inhibitors. Ann Oncol. 26: 1824-1829, 2015.
3. 3) Fukushima, S.: A review of adverse events caused by immune checkpoint inhibitors. Nihon Rinsho Meneki Gakkai Kaishi. 39: 30-36, 2016.
4. 4) Rudd, C.E., et al.: CD28 and CTLA-4 coreceptor expression and signal transduction. Immunol Rev. 229: 12-26, 2009.
5. 5) Tivol, E.A., et al.: Loss of CTLA-4 leads to massive lymphoproliferation and fatal multiorgan tissue destruction, revealing a critical negative regulatory role of CTLA-4. Immunity. 3: 541-547, 1995.