The percentage of MDSCs (6.1% ± 3.3% vs. 3.4% ± 1.8%, P = 0.023) (Fig. 7b) and the level of circulating IL-6 (20.1 ± 15.8 pg/ml vs. 7.9 ± 6.2 pg/ml, P = 0.027) (Fig. 7c) in the peripheral blood of CRLM patients (n = 20) are higher than the stage I CRC patients (n = 10). Here, IL6 is linked to colorectal carcinoma.