Elevated serum CA-125 levels can be detected in some patients with malignant diseases involving the breasts, lungs, ovaries, colon, and pancreas, as well as in others with non-malignant diseases, such as endometriosis, uterine myomas, ovarian cysts, hepatic cirrhosis, pleural effusions, peritonitis, pancreatitis, and heart failure [8–12]. The gene discussed is MUC16; the disease is Pleural effusion.