KLRB1 and glioblastoma: Cytotoxic T cells in glioblastoma express the NK lymphocytic gene KLRB1. TAMs express the ligand CLEC2D on the surface which serves as an inhibitor for the KLRB1 receptor to suppress their tumor lytic function57. The homophilic CD99-CD99 interaction was demonstrated by most TAMs in our analyses.