AQP9 and central nervous system cancer: In the current study, DWI parameters metrics derived from low to ultra-high b values based on mono-exponential model, IVIM model, DKI model and ultra-high b-value model were analyzed from three aspects: (1) their association with expression of histological molecular biomarkers including Ki-67, AQP1, AQP4, and AQP9; (2) if they could be taken as noninvasive surrogated indicators for depicting microenvironment as tumor progression; (3) their preoperative diagnosing ability to differentiate low- and high-grade gliomas.