SPP1 and ovarian carcinoma: Osteopontin, a N-linked glycoprotein family of calcified extra-cellular matrix–associated protein, has been discussed as a potential diagnostic biomarker for ovarian cancer and showed evidence of an association between levels of osteopontin in serum and ovarian cancer suggesting that it would be worthwhile for future research assessing its clinical usefulness (Kim et al. 2002; Bramwell et al. 2006).