PAX8 and neoplasm: Our immunohistochemistry show the DKO and TKO tumours to express WT1 but not PAX8, suggesting that they have either lost PAX8 expression during tumorigenesis, or may not arise in the secretory cells of the tubal fimbria– interestingly, in transgenic Pten−/−;Trp53LSL-R172H/+ mice, tumours were still able to form following removal of the fallopian tumours, suggesting that HGSC can arise in the ovaries24.