Methods: The primary literature and review articles were obtained through PUBMED searches of “ovarian cancer”, “biomarkers”, “CA125”, “circulating tumor DNA”, “BRCA”, “HER2”, “TROP2”, and “FOLR1.” Results and Conclusions: The detection and quantification of CA125, a protein biomarker, remains the primary test used in the clinic for ovarian cancer diagnosis and monitoring. This evidence concerns the gene MUC16 and ovarian cancer.