PDCD1 and central nervous system cancer: In addition, EGFR, programmed cell death protein 1 (PD-1), and PD-L1 are detected in 66.7%, 2.5%, and 0.1% of gliomas, respectively, and the corresponding detection rates in GBM were estimated as 63.1%, 4.9%, and 0.0%, respectively (Figure S2).