The widely used, classic, “gold standard” tumor biomarker, CA125, a high molecular weight glycoprotein, has a sensitivity between 50% and 60% with a specificity of 90% in early stage postmenopausal women, and expression of CA125 is enhanced in 90% of patients with epithelial ovarian cancer above normal levels [13–17]. Here, MUC16 is linked to ovarian carcinoma.