ELR-positive chemokines, including CXCL1 and CXCL5, induce cancer cell migration and invasion (35, 36); hence, we tested whether the secretion of CXCL1 and CXCL5 was downregulated in our cancer cell-macrophage cocultures, using the same experimental setup as before (Figure 4A). Here, CXCL1 is linked to cancer.