CCL2 and colorectal cancer: For example, CCL2- and CCL5-mediated recruitment of MDSCs have been reported at the inflammatory tumor microenvironment (TME) [38], as increased levels of intratumoral CCL2 were found in patients with colitis-associated colorectal cancer (CRC), adenocarcinomas, and adenomas [39], whereas increased expression of CCR2 (receptor of CCL2) was found on isolated MDSCs from ovarian, breast, or gastric cancer patients [40].