PDCD1 and cancer: Indeed, according to Youden’s index maximization criterion, we determined in the cSCC cohort that the presence of <62% Ecad+ cancer cells, and more than 55% Vim+ cancer cells, 36% CD80+ cancer cells, 74% CD155+ cancer cells, 37% Ecad−Vim+ cancer cells, 18% Ecad−CD80+ cancer cells, and 26% Ecad−CD155+ cancer cells might be risk factors for anti-PD-1/PD-L1 resistance (Supplementary Figs. 8a–e and 9a–d).