SPP1 and cancer: Notably, these cancer biomarkers functionally comprised of several cytokines (IL-6, MIF, TGF-α, TNFα), apoptosis-related proteins (sFas, sFasL, TRAIL), growth and angiogenic factors (FGF2, HGF, SCF, VEGF), hormones (leptin, prolactin) and other biomarkers (AFP, OPN), but not carcinoma antigens.