CCL13 and cancer: The recruitment of MDSCs to tumors is regulated by multiple chemoattractants secreted by cancer cells and stroma cells, such as CCL1‐3, CXCL1, CXCL5, CXCL8, and S100A8/9.[16] In this study, CXCL5 was identified to be significantly upregulated in the serum and tumor of mice following AB680 treatment, as confirmed by a 23‐cytokine immunoassay and ELISA.