To further examine the impact of Oligo-Fucoidan on IL-6 and CCL2 secretion from cancer cells, we treated HCT116 cells with etoposide and Oligo-Fucoidan (400 μg/ml) or etoposide alone for 24 h before incubating the cells in serum-free media for another 48 h (Fig. 5a). Here, IL6 is linked to cancer.