To further explore the relevance of cancer cell IC ligands in regulating CTL functions in the absence of additional stromal components, we isolated CD8+ T cells from the spleens of mice bearing epithelial or mesenchymal cSCCs and activated them in vitro with CD3/CD28 antibodies in the presence of epithelial or mesenchymal cancer cells (Fig. 3a). Here, CD8A is linked to cancer.