S100A8 and neoplasm: Immune cell alterations at the tumor site, and in nearby and distant organs, appear to depend on tumor-derived and immunomodulatory molecules, including GM-CSF, S100A8/A9 heterocomplex and chemokines, which target the Ras/MAPK, Jak/Stat, PI3K and TGFβ pathways [14, 25].