As for colorectal cancer, Naito et al (1998) have pointed out in a study of 131 patients that the number of intraepithelial CD8+ T cells (designated as CD8+T cells within cancer cell nests in this paper) has a more significant impact on patients' survival than that of CD8+ T cells in other locations within the tumour. The gene discussed is CD8A; the disease is colorectal cancer.