The expression of AQP1 in MM tumor cells is an independent prognostic factor to improve survival time in MM, high levels of AQP1 expression of MM tumor cells predict an increase in survival [87,88] while in other tumors the increase of AQP1 levels is associated with worse prognosis, including breast cancer, melanoma, urothelial carcinoma and pharynx squamous cell carcinoma [81]. Here, AQP1 is linked to urothelial carcinoma.