By comprehensive analysis of data for 10,294 samples, a recent study showed that MMR-deficient gliomas are characterized by a lack of prominent T cell infiltration, extensive intratumoral heterogeneity, poor patient survival, and a low rate of response to PD-1 blockade (54), reconfirming the ability of HSPA7 to predict the response to immunotherapy. The gene discussed is PDCD1; the disease is central nervous system cancer.