GDF15 and ovarian cancer: To date, many different biomarkers have been identified, including growth differentiation factor 15 (GDF-15), interleukin 6 (IL-6), Interleukin-6 receptor subunit alpha (IL-6 R alpha), vascular cell adhesion molecule 1 (VCAM-1), CD276 molecule (B7-H3), syndecan-1 (SDC1), and TEK receptor tyrosine kinase (Tie-2) for detection and monitoring of ovarian cancer [6–22].