CD274 and glioma: There were two studies that used the 31-gene signature in combination with programmed death ligand 1 (PD-L1) status (determined by CD274 expression) to classify tumours as PD-L1 high/radioresistant versus other in glioma (n = 511; n = 302 radiotherapy, n = 209 no radiotherapy) [21] and glioblastoma (n = 399; n = 284 radiotherapy, n = 115 no radiotherapy) [28] patients from the TCGA.