The cytokines secreted in the bioreactor (MCP-1/CCL2 [68, 69], ENA-78/CXCL5 [68, 70]) have been implicated in the cross-talk between cancer associated fibroblasts (CAFs) and tumor associated macrophages (TAMs) 71, 72 Within the co-cultures, we find additional cytokines that contribute to the establishment of an inflammatory tumor microenvironment, such as SPP1 [73], MCP-3 [68], RANTES [68, 74], IL-8 [69, 75]. The gene discussed is CCL2; the disease is cancer.