SPP1 and neoplasm: Based on all the results, we proposed a working model how CSFs promote tumor progression, that is, CSFs secrete plenty of TGF-β to maintain their activation state and enhance ECM remodeling; CSFs also highly express MIF to inhibit T cell-mediated antitumor immune response; MIF may also induce macrophage to secrete OPN/SPP1, thus further enhance the transition of normal fibroblasts to CSFs (Figure 7F).