S100A8 and neoplasm: In the distant premetastatic lung, TGF-β is one of the factors produced by tumor cells responsible for the production of the chemoattractants S100A8 and S100A9, which attract Mac1+ myeloid cells.(35) Through this mechanism, tumor cells also activated mitogen-activated protein kinase (MAPK) p38 to acquire migratory activity with pseudopodia for invasion (invadopodia).(35) In addition, TGF-β also induces angiopoietin-like 4 expression in cancer cells that are about to enter the circulation.