Cluster analysis was performed based on keyword co-occurrence analysis, and 17 clusters were finally established, mainly including regulatory T cell, macrophage, peptide vaccination, PD-1, CD8(+), chimeric antigen receptor, innate immunity, phase II trial, tumor microenvironment, tumor heterogeneity, immunotherapy, IDH mutation, glioma, natural killer cell, survival, and resistance. Here, CD8A is linked to central nervous system cancer.