CA9 and neoplasm: Due to this lack of patientselection, a therapeutic effect for the subset of the patient populationwith hypoxic tumors is potentially overlooked.36 In light of this, accurate assessment of hypoxia in clinicaland preclinical studies is essential.10,11,37,38 However, as also shownin our study, hypoxia and the hypoxic biomarker CAIX are distributedheterogeneously throughout the tumor.