IGFBP4 and metabolic syndrome: Based on the literature, we made an initial selection of 26 potentially interesting biomarkers with known estrogen-dependent secretion, representing clues for reproductive and developmental toxicity or links to cancer and metabolic syndrome (for instance: amphiregulin; ET-1; GCDFP-24 (PBCP); GCDFP-15 (PIP); MMP-2; PGE2; pS2 protein; SCF; TGF-ß; IL-18; Platelet-Derived Growth Factor (PDGF); EGF; endostatin; IGFBP-4).