AQP9 and central nervous system cancer: As the cell proliferation and the water transportation are highly suspected to influence the water diffusion properties in gliomas at extracellular, intracellular or transcellular space, Ki-67 or aquaporin (AQP) subtypes (AQP1, AQP4, AQP9) were welcomed molecular targets quantified by different DWI diffusion metrics (4, 5).