PDCD1 and neoplasm: Considering the importance of immune checkpoints in tumor immunotherapy and prognosis, we subsequently investigated the relationship between the expression of 12 immune checkpoints and the risk score of the predictive models, as shown in Fig. 7A and B. The risk score showed a negative correlation with PDCD1, CD274, PDCD1LG2, CTLA4, ICOS, HAVCR2, and LAG3.