MUC16 and cancer: CA125 is a high molecular weight transmembrane glycoprotein encoded by MUC16 gene, which is rarely secreted or not secreted by human body under normal conditions.[27,28] The level of CA125 is related to many factors, such as the inflammatory reaction of the body, the progress of malignant tumor, the amount of ascites, etc. When endometrial malignant lesions appear, the serum level can be abnormally elevated.