PDCD1 and central nervous system cancer: Interestingly, our results confirmed that MMD2, MCM3, MCM5, and MCM8 expression was significantly positively associated with the CD274, CTLA4, HAVCR2, LAG3, PDCD1, PDCD1LG2, TIGIT, and SIGLEC15, while, MCM4, MCM6, and MCM9 were significantly negatively correlated with CD274, CTLA4, HAVCR2, PDCD1, PDCD1LG12, TIGIT, and SIGLEC15, which suggested that MCMs has the potential to act as a predictive biomarker for the effectors of immune checkpoint blockade in glioma.