SPP1 and ovarian cancer: We have previously described and investigated a panel of six serologic protein biomarkers (leptin, prolactin (PROL), osteopontin (OPN), insulin-like growth factor II (IGF-II), macrophage migration inhibitory factor (MIF), and CA-125) for the detection of ovarian cancer with a sensitivity of 95.3% and specificity of 99.4% [11,12].