Because of the focal character of CAIX expression in the tumour tissue, performing the analysis on preoperative biopsies might be challenging, but visualisation of hypoxia and angiogenesis on FDG-PET/CT (fluorodeoxyglucose-positron emission tomography/computed tomography) scan and magnetic resonance imaging could be an alternative, as Berg et al.5 showed recently. This evidence concerns the gene CA9 and neoplasm.