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 neoplasm.