CA125 is a tumor marker, which belongs to the tumor markers of glycoantigens. Its specificity (i.e., which tumor it is elevated in) is not strong, that is, its elevation does not indicate a certain tumor for sure. In gynecology, for example, gynecological inflammation, uterine fibroids, ovarian cysts, all these conditions may cause an increase in CA125. If it is a benign tumor, most of the elevated levels will not be very high, but if it is a malignant tumor, it may be significantly elevated.