In one study, the immune analysis indicated that pembrolizumab anti-PD-1 monotherapy couldn’t induce an effector immune response in most GBM patients, likely because of immune-suppressive CD68+ macrophages preponderance in the tumor microenvironment and also insufficient T-cell frequency within the tumor microenvironment to eliminate the tumor (84). The gene discussed is PDCD1; the disease is glioblastoma.