PDCD1 and glioblastoma: In mice with glioblastoma, combining stereotactic radiotherapy with PD-1 blockade resulted in 75% pathologic complete response by activating macrophages, highlighting a novel immunologic mechanism underlying the interaction between radiotherapy and ICIs, though an international phase 3 trial demonstrated longer mOS from TMZ with radiotherapy than nivolumab with radiotherapy, leaving the SOC for glioblastoma unchanged as of now [46,47].