PDCD1 and cancer: Here, we integrated analyses of patients with cancer from The Cancer Genome Atlas (TCGA) cohort and newly established mouse preclinical anti–PD-1 therapy–refractory models (CT26 P3 or YUMM2.1 P3) and found that elevated NANOG expression in tumors could reprogram the tumor microenvironment (TME) into one that was immunologically nonresponsive to tumors.