AQP1, AQP3, AQP4, AQP5, AQP7, and AQP9 expression were evaluated because these AQPs are expressed in breast tumors and have begun to be characterized as having roles in breast cancer progression and metastasis [11,12,13,14,15,16,18,37,49,50,51]. This evidence concerns the gene AQP9 and breast cancer.