Here, we curated a core set of genes defining an immune activation (IA) CD8+ T effector cell signature22, 23, 24 to explore the relationship with a curated ECM/stromal signature expressed by mesenchymal cells, including but not limited to CAFs, within the TME across various solid tumours15,17,19 using molecular analysis of The Cancer Gene Atlas (TCGA). The gene discussed is CD8A; the disease is cancer.