AQP9 and ductal breast carcinoma in situ: Positive AQP3, AQP7 and AQP9 immunohistochemical stainings were observed in all the premalignant LCIS and DCIS regions (representative examples in Figure 3A and Figure 4A, respectively), as well as in the invasive ILC and IDC regions (representative examples in Figure 3B and Figure 4B, respectively).