See http://creativecommons.org/licenses/by-nc/4.0/. ORCID iDs Sofie Kirial Mørk http://orcid.org/0009-0000-1119-0047 Arianna Draghi http://orcid.org/0000-0002-5894-6750 Kalijn Bol http://orcid.org/0000-0003-4165-2040 Marco Donia http://orcid.org/0000-0003-4966-9752 Sine Reker Hadrup http://orcid.org/0000-0002-5937-4344 REFERENCES 1 Bagchi S, Yuan R, Engleman EG. Immune Checkpoint inhibitors for the treatment of cancer: clinical impact and mechanisms of response and resistance. Annu Rev Pathol Mech Dis 2021;16:223–49. 2 Twomey JD, Zhang B. Cancer Immunotherapy update: FDA- approved Checkpoint inhibitors and companion diagnostics. AAPS J 2021;23:39. 3 Esfahani K, Roudaia L, Buhlaiga N, et al. A review of cancer Immunotherapy: from the past, to the present, to the future. Curr Oncol 2020;27:S87–97. 4 Snyder A, Makarov V, Merghoub T, et al. Genetic basis for clinical response to CTLA- 4 blockade in Melanoma. N Engl J Med 2014;371:2189–99.