In fact, although CA-125 is routinely used in clinical practice as a HGS-EOC biomarker (CA-125 cut-off > 35 U/mL), it is well demonstrated that its sensitivity and specificity are poor as its concentration in the bloodstream can also increase in benign conditions, such as endometriosis or pelvic inflammatory disease, as well as in other malignant tumors—lung, breast and gastrointestinal cancers [33,34,35]. Here, MUC16 is linked to endometriosis.