PDCD1 and neoplasm: TCRs targeting KRAS G12D have been isolated and identified from patients’ blood after tumor vaccine application.114 The latest clinical trial of mRNA-4157 in high-risk melanoma showed that the combination with mRNA-4157 and anti-programmed cell death protein 1 (PD-1) greatly prolonged the distant-metastasis free survival and reduced the risk of developing distant metastases or death by 65% compared to pembrolizumab alone.