PDCD1 and neoplasm: There were four study groups: The first was therapy delivered as a monotherapy to resected tumours; the second group was a combination mRNA vaccine with Pembrolizumab (anti-PD-1) for patients with advanced and metastatic tumours; the third group were ICI naïve microsatellite colon cancer and HPV-negative HNSCC; and the fourth group resected melanoma patients.