Increased CCL5 expression, infiltration of Treg cells, and apoptosis of CD8+ T cells in human colorectal tissues. Increased CCL5 expression, infiltration of Treg cells, and apoptosis of CD8+ T cells in human colorectal tissues. A, the CCL5 gene expression in tumor part and nontumor part of colon in 22 patients with CRC was measured by qRT-PCR. Relative expression levels were adjusted by the level of β-actin mRNA for each sample. All data represent mean of 2−ΔCt. B, the percentage of CD4+CD25+Foxp3+ Treg cells and (C) Annexin V+CD8+ T cells in PBLs and TILs from patients with CRC or healthy volunteers were determined by flow cytometry. Each dot represents one individual sample and data show mean ± SEM. **, P < 0.01 and NS, not statistically significant. Li-Yuan Chang et al. Cancer Res 2012;72:1092-1102 ©2012 by American Association for Cancer Research