CA9 and female reproductive organ cancer: In summary, the data from our studies on the detection of micrometastasis in three types of gynecological cancer employing dual biomarkers clearly suggest that qRT-PCR seems to exhibit a slightly better diagnostic accuracy compared to IHC and corroborate previous studies, while the epithelial marker of CK19 when directly compared to the CA9 tumor-specific marker displays a rather consistent pattern of accurate detection of micrometastasis, which is independent of other variable tumor parameters, such as hypoxia and oxygen levels.