Finally, Trigueros-Motos et al., [78] used the capecitabine catabolite 5′-deoxy-5-fluorouridine (5′-DFUR) (a nucleoside analog used in the chemotherapy of solid tumors) to demonstrate that AQP3 is required for cytotoxic activity of 5′-DFUR in the breast cancer cell line MCF7 and that this aquaporin is implicated in cell volume increase and cell cycle arrest. This evidence concerns the gene AQP3 and breast carcinoma.