CXCL5 expression (red) in the rat colon cancer cell line CC531S (nuclei, green). Low level of CXCL5 expression is associated with aggressive tumor growth in a rat model and predicts decreased survival rates in patients treated with surgery for colorectal cancer. A positive correlation between levels of CXCL5 and intratumoral CD8+ T-cell infiltration in colon cancer suggests that CXCL5 is involved in themigration of immune cells into the tumor and might be implicated in the antitumor immune response. For further details, please see Speetjens and coworkers 2276 in this issue.