NTSR1 and glioblastoma: We aimed to evaluate the robustness, suitability, and feasibility of NO2‐Rosol for imaging hypoxia in vitro and in vivo via assessing NTR activity in diverse GBM models under relevant oxygenation levels (pO2 = 2.0%) within physiological hypoxic conditions that mimic oxygenation levels in GBM tumor tissue in the brain.