This schematic depicts protein markers and functional properties that are
enriched in tumor-reactive CD8+ T cells (i.e. T cells that express a
tumor-reactive T cell receptor (TCR), irrespective of their functional capacity)
relative to bystander CD8+ T cells at the tumor site. Note that none
of these characteristics by themselves identify tumor-reactive CD8+ T
cells with absolute precision and that for some of these markers (4-1BB, GITR,
and CXC-chemokine ligand 13 (CXCL13)), the evidence is less well established.
LAG3, lymphocyte activation gene 3 protein; PD1, programmed cell death protein
1; TIM3, T-cell immunoglobulin mucin receptor 3.