For example, co-culture of various types of cancer cells, including HCC and glioblastoma with CSC-conditioned media, promoted the release of numerous chemokines and cytokines favoring tumorigenic macrophage factors [98,99,100,101], including CCL2, CCL5, CSF1, GDF-15, IL-13, TGF-β, and WISP1 (Figure 2). Here, CCL2 is linked to glioblastoma.