To evaluate whether miR98 reduction contributes to CCL18 enhanced breast cancer metastasis in vivo, we inoculated MDA-MB-231 breast cancer cells that were infected with lentivirus carrying NC or miR98 and stimulated by CCL18 (20 ng/ml) for 14 d into the mammary fat pads of nude mice. Here, CCL18 is linked to breast carcinoma.